diff --git a/Makefile b/Makefile
index db3dff4f2..0bac63457 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ export GO111MODULE:=on
 .PHONY: all libs exe test
 
 all: libs
-	./scripts/go_executable_build.sh
+	./scripts/go_executable_build.sh -S
 
 libs:
 	make -C $(TOP)/mcl -j8
diff --git a/core/tx_list.go b/core/tx_list.go
index b35d049cf..0aa78f841 100644
--- a/core/tx_list.go
+++ b/core/tx_list.go
@@ -262,11 +262,11 @@ func (l *txList) Add(tx types.PoolTransaction, priceBump uint64) (bool, types.Po
 		}
 	}
 	// Otherwise overwrite the old transaction with the current one
-	l.txs.Put(tx)
 	cost, err := tx.Cost()
 	if err != nil {
 		return false, nil
 	}
+	l.txs.Put(tx)
 	if l.costcap.Cmp(cost) < 0 {
 		l.costcap = cost
 	}
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 1cee48a92..f06127e15 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -369,8 +369,13 @@ func (pool *TxPool) loop() {
 				}
 				// Any non-locals old enough should be removed
 				if time.Since(pool.beats[addr]) > pool.config.Lifetime {
+					b32addr, err := hmyCommon.AddressToBech32(addr)
+					if err != nil {
+						b32addr = "unknown"
+					}
 					for _, tx := range pool.queue[addr].Flatten() {
 						pool.removeTx(tx.Hash(), true)
+						pool.txErrorSink.Add(tx, fmt.Errorf("removed transaction for inactive account %v", b32addr))
 					}
 				}
 			}
@@ -557,6 +562,8 @@ func (pool *TxPool) SetGasPrice(price *big.Int) {
 	pool.gasPrice = price
 	for _, tx := range pool.priced.Cap(price, pool.locals) {
 		pool.removeTx(tx.Hash(), false)
+		pool.txErrorSink.Add(tx,
+			fmt.Errorf("dropped transaction below new gas price threshold of %v", price.String()))
 	}
 	utils.Logger().Info().Str("price", price.String()).Msg("Transaction pool price threshold updated")
 }
@@ -868,7 +875,7 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 	// If the transaction is already known, discard it
 	hash := tx.Hash()
 	if pool.all.Get(hash) != nil {
-		logger.Warn().Str("hash", hash.Hex()).Msg("Discarding already known transaction")
+		logger.Info().Str("hash", hash.Hex()).Msg("Discarding already known transaction")
 		return false, errors.WithMessagef(ErrKnownTransaction, "transaction hash %x", hash)
 	}
 	// If the transaction fails basic validation, discard it
@@ -893,12 +900,16 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 		// New transaction is better than our worse ones, make room for it
 		drop := pool.priced.Discard(pool.all.Count()-int(pool.config.GlobalSlots+pool.config.GlobalQueue-1), pool.locals)
 		for _, tx := range drop {
+			gasPrice := new(big.Float).SetInt64(tx.GasPrice().Int64())
+			gasPrice = gasPrice.Mul(gasPrice, new(big.Float).SetFloat64(1e-9)) // Gas-price is in Nano
+			pool.removeTx(tx.Hash(), false)
+			underpricedTxCounter.Inc(1)
+			pool.txErrorSink.Add(tx,
+				errors.WithMessagef(ErrUnderpriced, "transaction gas-price is %.18f ONE in full transaction pool", gasPrice))
 			logger.Warn().
 				Str("hash", tx.Hash().Hex()).
 				Str("price", tx.GasPrice().String()).
 				Msg("Discarding freshly underpriced transaction")
-			underpricedTxCounter.Inc(1)
-			pool.removeTx(tx.Hash(), false)
 		}
 	}
 	// If the transaction is replacing an already pending one, do directly
@@ -915,15 +926,23 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 			pool.all.Remove(old.Hash())
 			pool.priced.Removed()
 			pendingReplaceCounter.Inc(1)
+			pool.txErrorSink.Add(old,
+				fmt.Errorf("replaced transaction, new transaction %v has same nonce & higher price", tx.Hash().String()))
+			logger.Info().
+				Str("hash", old.Hash().String()).
+				Str("new-tx-hash", tx.Hash().String()).
+				Str("price", old.GasPrice().String()).
+				Msg("Replaced transaction")
 		}
 		pool.all.Add(tx)
 		pool.priced.Put(tx)
 		pool.journalTx(from, tx)
 
-		logger.Info().
+		logger.Warn().
 			Str("hash", tx.Hash().Hex()).
 			Interface("from", from).
 			Interface("to", tx.To()).
+			Str("price", tx.GasPrice().String()).
 			Msg("Pooled new executable transaction")
 
 		// We've directly injected a replacement transaction, notify subsystems
@@ -932,7 +951,7 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 		return old != nil, nil
 	}
 	// New transaction isn't replacing a pending one, push into queue
-	replace, err := pool.enqueueTx(hash, tx)
+	replace, err := pool.enqueueTx(tx)
 	if err != nil {
 		return false, err
 	}
@@ -945,7 +964,7 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 	}
 	pool.journalTx(from, tx)
 
-	logger.Info().
+	logger.Warn().
 		Str("hash", hash.Hex()).
 		Interface("from", from).
 		Interface("to", tx.To()).
@@ -956,7 +975,7 @@ func (pool *TxPool) add(tx types.PoolTransaction, local bool) (bool, error) {
 // enqueueTx inserts a new transaction into the non-executable transaction queue.
 //
 // Note, this method assumes the pool lock is held!
-func (pool *TxPool) enqueueTx(hash common.Hash, tx types.PoolTransaction) (bool, error) {
+func (pool *TxPool) enqueueTx(tx types.PoolTransaction) (bool, error) {
 	// Try to insert the transaction into the future queue
 	from, _ := tx.SenderAddress() // already validated
 	if pool.queue[from] == nil {
@@ -973,8 +992,15 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx types.PoolTransaction) (bool,
 		pool.all.Remove(old.Hash())
 		pool.priced.Removed()
 		queuedReplaceCounter.Inc(1)
-	}
-	if pool.all.Get(hash) == nil {
+		pool.txErrorSink.Add(old,
+			fmt.Errorf("replaced enqueued non-executable transaction, new transaction %v has same nonce & higher price", tx.Hash().String()))
+		utils.Logger().Info().
+			Str("hash", old.Hash().String()).
+			Str("new-tx-hash", tx.Hash().String()).
+			Str("price", old.GasPrice().String()).
+			Msg("Replaced enqueued non-executable transaction")
+	}
+	if pool.all.Get(tx.Hash()) == nil {
 		pool.all.Add(tx)
 		pool.priced.Put(tx)
 	}
@@ -997,7 +1023,7 @@ func (pool *TxPool) journalTx(from common.Address, tx types.PoolTransaction) {
 // and returns whether it was inserted or an older was better.
 //
 // Note, this method assumes the pool lock is held!
-func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx types.PoolTransaction) bool {
+func (pool *TxPool) promoteTx(addr common.Address, tx types.PoolTransaction) bool {
 	// Try to insert the transaction into the pending queue
 	if pool.pending[addr] == nil {
 		pool.pending[addr] = newTxList(true)
@@ -1007,21 +1033,29 @@ func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx types.Po
 	inserted, old := list.Add(tx, pool.config.PriceBump)
 	if !inserted {
 		// An older transaction was better, discard this
-		pool.all.Remove(hash)
+		pool.all.Remove(tx.Hash())
 		pool.priced.Removed()
-
 		pendingDiscardCounter.Inc(1)
+		pool.txErrorSink.Add(tx, fmt.Errorf("could not promote to executable"))
+		utils.Logger().Info().
+			Str("hash", tx.Hash().String()).
+			Msg("Could not promote to executable")
 		return false
 	}
 	// Otherwise discard any previous transaction and mark this
 	if old != nil {
 		pool.all.Remove(old.Hash())
 		pool.priced.Removed()
-
 		pendingReplaceCounter.Inc(1)
+		pool.txErrorSink.Add(old,
+			fmt.Errorf("did not promote to executable, existing transaction %v has same nonce & higher price", tx.Hash().String()))
+		utils.Logger().Info().
+			Str("hash", old.Hash().String()).
+			Str("existing-tx-hash", tx.Hash().String()).
+			Msg("Did not promote to executable, new transaction has higher price")
 	}
 	// Failsafe to work around direct pending inserts (tests)
-	if pool.all.Get(hash) == nil {
+	if pool.all.Get(tx.Hash()) == nil {
 		pool.all.Add(tx)
 		pool.priced.Put(tx)
 	}
@@ -1069,6 +1103,7 @@ func (pool *TxPool) addTx(tx types.PoolTransaction, local bool) error {
 	replace, err := pool.add(tx, local)
 	if err != nil {
 		errCause := errors.Cause(err)
+		// Ignore known transaction for tx rebroadcast case.
 		if errCause != ErrKnownTransaction {
 			pool.txErrorSink.Add(tx, err)
 		}
@@ -1104,6 +1139,7 @@ func (pool *TxPool) addTxsLocked(txs types.PoolTransactions, local bool) []error
 			dirty[from] = struct{}{}
 		}
 		errCause := errors.Cause(err)
+		// Ignore known transaction for tx rebroadcast case.
 		if err != nil && errCause != ErrKnownTransaction {
 			pool.txErrorSink.Add(tx, err)
 		}
@@ -1173,7 +1209,7 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 			}
 			// Postpone any invalidated transactions
 			for _, tx := range invalids {
-				if _, err := pool.enqueueTx(tx.Hash(), tx); err != nil {
+				if _, err := pool.enqueueTx(tx); err != nil {
 					pool.txErrorSink.Add(tx, err)
 				}
 			}
@@ -1220,24 +1256,26 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		nonce := pool.currentState.GetNonce(addr)
 		for _, tx := range list.Forward(nonce) {
 			hash := tx.Hash()
-			logger.Info().Str("hash", hash.Hex()).Msg("Removed old queued transaction")
 			pool.all.Remove(hash)
 			pool.priced.Removed()
+			logger.Info().Str("hash", hash.Hex()).Msg("Removed old queued transaction")
+			// Do not report to error sink as old txs are on chain or meaningful error caught elsewhere.
 		}
 		// Drop all transactions that are too costly (low balance or out of gas)
 		drops, _ := list.Filter(pool.currentState.GetBalance(addr), pool.currentMaxGas)
 		for _, tx := range drops {
 			hash := tx.Hash()
-			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable queued transaction")
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 			queuedNofundsCounter.Inc(1)
+			pool.txErrorSink.Add(tx, fmt.Errorf("removed unpayable queued transaction"))
+			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable queued transaction")
 		}
 		// Gather all executable transactions and promote them
 		for _, tx := range list.Ready(pool.pendingState.GetNonce(addr)) {
 			hash := tx.Hash()
-			if pool.promoteTx(addr, hash, tx) {
-				logger.Info().Str("hash", hash.Hex()).Msg("Promoting queued transaction")
+			if pool.promoteTx(addr, tx) {
+				logger.Warn().Str("hash", hash.Hex()).Msg("Promoting queued transaction")
 				promoted = append(promoted, tx)
 			}
 		}
@@ -1245,11 +1283,11 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		if !pool.locals.contains(addr) {
 			for _, tx := range list.Cap(int(pool.config.AccountQueue)) {
 				hash := tx.Hash()
-				logger.Warn().Str("hash", hash.Hex()).Msg("Removed cap-exceeding queued transaction")
-				pool.txErrorSink.Add(tx, fmt.Errorf("exceeds cap for queued transactions for account %s", addr.String()))
 				pool.all.Remove(hash)
 				pool.priced.Removed()
 				queuedRateLimitCounter.Inc(1)
+				pool.txErrorSink.Add(tx, fmt.Errorf("exceeds cap for queued transactions for account %s", addr.String()))
+				logger.Warn().Str("hash", hash.Hex()).Msg("Removed cap-exceeding queued transaction")
 			}
 		}
 		// Delete the entire queue entry if it became empty.
@@ -1295,9 +1333,9 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 						for _, tx := range list.Cap(list.Len() - 1) {
 							// Drop the transaction from the global pools too
 							hash := tx.Hash()
-							pool.txErrorSink.Add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
 							pool.all.Remove(hash)
 							pool.priced.Removed()
+							pool.txErrorSink.Add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
 
 							// Update the account nonce to the dropped transaction
 							if nonce := tx.Nonce(); pool.pendingState.GetNonce(offenders[i]) > nonce {
@@ -1318,9 +1356,9 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 					for _, tx := range list.Cap(list.Len() - 1) {
 						// Drop the transaction from the global pools too
 						hash := tx.Hash()
-						pool.txErrorSink.Add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
 						pool.all.Remove(hash)
 						pool.priced.Removed()
+						pool.txErrorSink.Add(tx, fmt.Errorf("fairness-exceeding pending transaction"))
 
 						// Update the account nonce to the dropped transaction
 						if nonce := tx.Nonce(); pool.pendingState.GetNonce(addr) > nonce {
@@ -1391,23 +1429,25 @@ func (pool *TxPool) demoteUnexecutables() {
 		// Drop all transactions that are deemed too old (low nonce)
 		for _, tx := range list.Forward(nonce) {
 			hash := tx.Hash()
-			logger.Info().Str("hash", hash.Hex()).Msg("Removed old pending transaction")
 			pool.all.Remove(hash)
 			pool.priced.Removed()
+			logger.Info().Str("hash", hash.Hex()).Msg("Removed old pending transaction")
+			// Do not report to error sink as old txs are on chain or meaningful error caught elsewhere.
 		}
 		// Drop all transactions that are too costly (low balance or out of gas), and queue any invalids back for later
 		drops, invalids := list.Filter(pool.currentState.GetBalance(addr), pool.currentMaxGas)
 		for _, tx := range drops {
 			hash := tx.Hash()
-			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable pending transaction")
 			pool.all.Remove(hash)
 			pool.priced.Removed()
 			pendingNofundsCounter.Inc(1)
+			pool.txErrorSink.Add(tx, fmt.Errorf("removed unpayable pending transaction"))
+			logger.Warn().Str("hash", hash.Hex()).Msg("Removed unpayable pending transaction")
 		}
 		for _, tx := range invalids {
 			hash := tx.Hash()
-			logger.Info().Str("hash", hash.Hex()).Msg("Demoting pending transaction")
-			if _, err := pool.enqueueTx(hash, tx); err != nil {
+			logger.Warn().Str("hash", hash.Hex()).Msg("Demoting pending transaction")
+			if _, err := pool.enqueueTx(tx); err != nil {
 				pool.txErrorSink.Add(tx, err)
 			}
 		}
@@ -1416,7 +1456,7 @@ func (pool *TxPool) demoteUnexecutables() {
 			for _, tx := range list.Cap(0) {
 				hash := tx.Hash()
 				logger.Error().Str("hash", hash.Hex()).Msg("Demoting invalidated transaction")
-				if _, err := pool.enqueueTx(hash, tx); err != nil {
+				if _, err := pool.enqueueTx(tx); err != nil {
 					pool.txErrorSink.Add(tx, err)
 				}
 			}
diff --git a/core/tx_pool_test.go b/core/tx_pool_test.go
index f7a478b91..55a999a1d 100644
--- a/core/tx_pool_test.go
+++ b/core/tx_pool_test.go
@@ -505,7 +505,7 @@ func TestTransactionQueue(t *testing.T) {
 	from, _ := deriveSender(tx)
 	pool.currentState.AddBalance(from, big.NewInt(1000))
 	pool.lockedReset(nil, nil)
-	pool.enqueueTx(tx.Hash(), tx)
+	pool.enqueueTx(tx)
 
 	pool.promoteExecutables([]common.Address{from})
 	if len(pool.pending) != 1 {
@@ -515,7 +515,7 @@ func TestTransactionQueue(t *testing.T) {
 	tx = transaction(0, 1, 100, key)
 	from, _ = deriveSender(tx)
 	pool.currentState.SetNonce(from, 2)
-	pool.enqueueTx(tx.Hash(), tx)
+	pool.enqueueTx(tx)
 	pool.promoteExecutables([]common.Address{from})
 	if _, ok := pool.pending[from].txs.items[tx.Nonce()]; ok {
 		t.Error("expected transaction to be in tx pool")
@@ -535,9 +535,9 @@ func TestTransactionQueue(t *testing.T) {
 	pool.currentState.AddBalance(from, big.NewInt(1000))
 	pool.lockedReset(nil, nil)
 
-	pool.enqueueTx(tx.Hash(), tx1)
-	pool.enqueueTx(tx.Hash(), tx2)
-	pool.enqueueTx(tx.Hash(), tx3)
+	pool.enqueueTx(tx1)
+	pool.enqueueTx(tx2)
+	pool.enqueueTx(tx3)
 
 	pool.promoteExecutables([]common.Address{from})
 
@@ -718,12 +718,12 @@ func TestTransactionDropping(t *testing.T) {
 		tx11 = transaction(0, 11, 200, key)
 		tx12 = transaction(0, 12, 300, key)
 	)
-	pool.promoteTx(account, tx0.Hash(), tx0)
-	pool.promoteTx(account, tx1.Hash(), tx1)
-	pool.promoteTx(account, tx2.Hash(), tx2)
-	pool.enqueueTx(tx10.Hash(), tx10)
-	pool.enqueueTx(tx11.Hash(), tx11)
-	pool.enqueueTx(tx12.Hash(), tx12)
+	pool.promoteTx(account, tx0)
+	pool.promoteTx(account, tx1)
+	pool.promoteTx(account, tx2)
+	pool.enqueueTx(tx10)
+	pool.enqueueTx(tx11)
+	pool.enqueueTx(tx12)
 
 	// Check that pre and post validations leave the pool as is
 	if pool.pending[account].Len() != 3 {
@@ -1524,7 +1524,7 @@ func benchmarkPendingDemotion(b *testing.B, size int) {
 
 	for i := 0; i < size; i++ {
 		tx := transaction(0, uint64(i), 100000, key)
-		pool.promoteTx(account, tx.Hash(), tx)
+		pool.promoteTx(account, tx)
 	}
 	// Benchmark the speed of pool validation
 	b.ResetTimer()
@@ -1549,7 +1549,7 @@ func benchmarkFuturePromotion(b *testing.B, size int) {
 
 	for i := 0; i < size; i++ {
 		tx := transaction(0, uint64(1+i), 100000, key)
-		pool.enqueueTx(tx.Hash(), tx)
+		pool.enqueueTx(tx)
 	}
 	// Benchmark the speed of pool validation
 	b.ResetTimer()
diff --git a/scripts/go_executable_build.sh b/scripts/go_executable_build.sh
index cef44c7ba..d42e0c513 100755
--- a/scripts/go_executable_build.sh
+++ b/scripts/go_executable_build.sh
@@ -244,7 +244,7 @@ function release
 
 
 ################################ MAIN FUNCTION ##############################
-while getopts "hp:a:o:b:f:rtvsd" option; do
+while getopts "hp:a:o:b:f:rtvsdS" option; do
    case $option in
       h) usage ;;
       p) PROFILE=$OPTARG ;;
diff --git a/test/deploy.sh b/test/deploy.sh
index d1045dcc4..c1d33d3e8 100755
--- a/test/deploy.sh
+++ b/test/deploy.sh
@@ -126,7 +126,7 @@ cleanup
 # Also it's recommended to use `go build` for testing the whole exe. 
 if [ "${NOBUILD}" != "true" ]; then
    pushd $ROOT
-   scripts/go_executable_build.sh
+   scripts/go_executable_build.sh -S
    popd
 fi