diff --git a/packages/executor/src/entities/MempoolEntry.ts b/packages/executor/src/entities/MempoolEntry.ts
index 15c805d9..0c37f316 100644
--- a/packages/executor/src/entities/MempoolEntry.ts
+++ b/packages/executor/src/entities/MempoolEntry.ts
@@ -123,6 +123,7 @@ export class MempoolEntry implements IMempoolEntry {
    * @returns boolaen
    */
   canReplace(existingEntry: MempoolEntry): boolean {
+    if (existingEntry.status > MempoolEntryStatus.OnChain) return true;
     if (!this.isEqual(existingEntry)) return false;
     if (
       BigNumber.from(this.userOp.maxPriorityFeePerGas).lt(
diff --git a/packages/executor/src/modules/eth.ts b/packages/executor/src/modules/eth.ts
index 333551a0..48939854 100644
--- a/packages/executor/src/modules/eth.ts
+++ b/packages/executor/src/modules/eth.ts
@@ -60,7 +60,7 @@ export class Eth {
     }
 
     // mantle
-    if ([5000, 5001].includes(this.chainId)) {
+    if ([5000, 5001, 5003].includes(this.chainId)) {
       this.pvgEstimator = estimateMantlePVG(this.provider);
     }
 
diff --git a/packages/executor/src/services/BundlingService/relayers/base.ts b/packages/executor/src/services/BundlingService/relayers/base.ts
index d2f6ff41..68d7e56a 100644
--- a/packages/executor/src/services/BundlingService/relayers/base.ts
+++ b/packages/executor/src/services/BundlingService/relayers/base.ts
@@ -183,7 +183,7 @@ export abstract class BaseRelayer implements IRelayingMode {
     if (this.networkConfig.skipBundleValidation) return true;
     try {
       // eslint-disable-next-line @typescript-eslint/no-unused-vars
-      const { gasLimit, ...txWithoutGasLimit } = transactionRequest;
+      const { gasLimit: _, ...txWithoutGasLimit } = transactionRequest;
       // some chains, like Bifrost, don't allow setting gasLimit in estimateGas
       await relayer.estimateGas(txWithoutGasLimit);
       return true;
diff --git a/packages/executor/src/services/BundlingService/relayers/classic.ts b/packages/executor/src/services/BundlingService/relayers/classic.ts
index a67178b2..45531127 100644
--- a/packages/executor/src/services/BundlingService/relayers/classic.ts
+++ b/packages/executor/src/services/BundlingService/relayers/classic.ts
@@ -87,10 +87,15 @@ export class ClassicRelayer extends BaseRelayer {
       if (!this.config.testingMode) {
         // check for execution revert
 
-        if (
-          !(await this.validateBundle(relayer, entries, transactionRequest))
-        ) {
-          return;
+        if (this.chainId == 5003) {
+          const { gasLimit: _, ...txWithoutGasLimit } = transactionRequest;
+          transaction.gasLimit = await relayer.estimateGas(txWithoutGasLimit);
+        } else {
+          if (
+            !(await this.validateBundle(relayer, entries, transactionRequest))
+          ) {
+            return;
+          }
         }
 
         this.logger.debug(
diff --git a/packages/executor/src/services/UserOpValidation/validators/estimation.ts b/packages/executor/src/services/UserOpValidation/validators/estimation.ts
index 7ca7ebec..f3b42fcf 100644
--- a/packages/executor/src/services/UserOpValidation/validators/estimation.ts
+++ b/packages/executor/src/services/UserOpValidation/validators/estimation.ts
@@ -53,13 +53,17 @@ export class EstimationService {
       this.provider
     );
 
-    const errorResult = await entryPointContract.callStatic
-      .simulateHandleOp(userOp, AddressZero, BytesZero, {
-        gasLimit: getUserOpGasLimit(
+    const gasLimit = this.networkConfig.gasFeeInSimulation
+      ? getUserOpGasLimit(
           userOp,
           constants.Zero,
           this.networkConfig.estimationGasLimit
-        ),
+        )
+      : undefined;
+
+    const errorResult = await entryPointContract.callStatic
+      .simulateHandleOp(userOp, AddressZero, BytesZero, {
+        gasLimit,
       })
       .catch((e: any) => nonGethErrorHandler(entryPointContract, e));
 
@@ -97,17 +101,22 @@ export class EstimationService {
       forwarderABI,
       this.provider
     );
+
+    const gasLimit = this.networkConfig.gasFeeInSimulation
+      ? getUserOpGasLimit(
+          userOp,
+          constants.Zero,
+          this.networkConfig.estimationGasLimit
+        )
+      : undefined;
+
     const data = await this.provider.call({
       to: this.networkConfig.entryPointForwarder,
       data: forwarder.interface.encodeFunctionData("forward", [
         entryPoint,
         simulateData,
       ]),
-      gasLimit: getUserOpGasLimit(
-        userOp,
-        BigNumber.from(105000),
-        this.networkConfig.estimationGasLimit
-      ),
+      gasLimit,
     });
 
     const error = entryPointContract.interface.parseError(data);
diff --git a/packages/executor/src/services/UserOpValidation/validators/unsafe.ts b/packages/executor/src/services/UserOpValidation/validators/unsafe.ts
index 9d63ae8a..d3aefe43 100644
--- a/packages/executor/src/services/UserOpValidation/validators/unsafe.ts
+++ b/packages/executor/src/services/UserOpValidation/validators/unsafe.ts
@@ -21,13 +21,18 @@ export class UnsafeValidationService {
       entryPoint,
       this.provider
     );
-    const errorResult = await entryPointContract.callStatic
-      .simulateValidation(userOp, {
-        gasLimit: getUserOpGasLimit(
+
+    const gasLimit = this.networkConfig.gasFeeInSimulation
+      ? getUserOpGasLimit(
           userOp,
           constants.Zero,
           this.networkConfig.estimationGasLimit
-        ),
+        )
+      : undefined;
+
+    const errorResult = await entryPointContract.callStatic
+      .simulateValidation(userOp, {
+        gasLimit,
       })
       .catch((e: any) => nonGethErrorHandler(entryPointContract, e));
     return parseErrorResult(userOp, errorResult);
@@ -52,17 +57,22 @@ export class UnsafeValidationService {
       forwarderABI,
       this.provider
     );
+
+    const gasLimit = this.networkConfig.gasFeeInSimulation
+      ? getUserOpGasLimit(
+          userOp,
+          constants.Zero,
+          this.networkConfig.estimationGasLimit
+        )
+      : undefined;
+
     const data = await this.provider.call({
       to: this.networkConfig.entryPointForwarder,
       data: forwarder.interface.encodeFunctionData("forward", [
         entryPoint,
         validationData,
       ]),
-      gasLimit: getUserOpGasLimit(
-        userOp,
-        constants.Zero,
-        this.networkConfig.estimationGasLimit
-      ),
+      gasLimit,
     });
     const error = entryPointContract.interface.parseError(data);
     return parseErrorResult(userOp, {
diff --git a/packages/params/src/gas-price-oracles/oracles/index.ts b/packages/params/src/gas-price-oracles/oracles/index.ts
index 38881455..b4899909 100644
--- a/packages/params/src/gas-price-oracles/oracles/index.ts
+++ b/packages/params/src/gas-price-oracles/oracles/index.ts
@@ -23,4 +23,5 @@ export const oracles: {
   8453: getBaseGasFee,
   888888888: getAncient8GasFee,
   59144: getEthGasPrice,
+  5003: getMantleGasFee,
 };