I have a 98 Honda Accord sedan EX 4 cylinder and at this time after the car has ran awhile and heated up when you take off from a stop around 3800-4000 on the tach it is like the engine is hitting a rev limiter. I have changed the VTEC modulator, plugs, and plug wires as well.

Is it possible there could be a issue between the transmission and the VTEC mod? Also when this happens I can place the car in neutral and rev the engine it will still surge around 3800-4000. This started when a piece of firewood fell of a truck and the cars in front of me missed it and when I seen it I tried to strattle it with the car and it bounced around underneath the car.

 

Your check engine light must be on. Get the code pulled from autozone or your dealer. If you go to autozone just post the code here and we can help you.

 

The check engine light is on and where I had it at the dealership previously it shows the code for the VTEC modulator and the other is for the oxygen sensor where I had the converter changed along with the install of a Bosch oxygen sensor and the dealership states the reason it is on for is where Honda parts was not used. Not for sure on this what do you think?

I have heard that the wires may be crossed on the oxygen sensor and this is why the code is coming up for this. They removed the VTEC mod and informed me that it is testing good so that tells me it is something prior to the mod?

 

i dont know about why the engine would do that, but you said that it "bounced around under there", well if it did, id also check your engine mounts. it might have busted that, hope not

 

the dealer is right, using non honda O2 sensors may cause the ECU to throw codes. IMHO it just isn't worth it to use non Honda parts unless they are of better quality than the Honda ones.

 

Okay I went today and hooked up to get the DTC Codes and they are listed below.

P1259 Manufacurer Contrl.-Fuel Air Metering
P0137 02 Sensor- Circuit Low Volts (Bank 1 Sensor 2)

As far as the 02 sensor it was installed May of last year. Would it take this long to start affecting the VTEC mod? On the 02 sensor code I am thinking that it may be the wrong model or could be wired wrong? Any suggestions.

Just like today after traveling and the engine getting warm at 3800 on the tach the engine surges or if you are on the interstate and you floor the gas pedal it feels like the transmission gears down and it continues to slow down until you let off the gas and then it jumps back up like nothing is wrong. That is where I thought it may be the tranny but I can put the car in neutral and rev it and it will not go past 3800 and starts surging. When I first start the car I can rev it and it will not act like this.

 

Just to point something out, the rev limit while in neutral (and not moving) is lower than the redline, although I forget what it's set at. It's somewhere in the vicinity of 4000 though.

I know this holds true for 6th gen automatics, and I was told it was the same for 5-spds.

 

P1259 comes back as Vtec System Malfunction
P0137 comes back as O2 sensor Low Voltage Bank1 sensor2

One may be effecting both
P0137 refers to the rear (unfortunately the more expensive) heated O2 sensor. The system is not seeing the voltage signal it expects to see from it. This can be caused by a weak heater (sensor never reaches operating temp), damage to the harness to the sensor or even being wired wrong. Was this a plug-n-play Bosch or did you have to splice & dice?

Although it's a stretch, it could be throwing the ECM into fail-safe, thus fixing the a/f ratio and limiting the engine RPM's

P

 

Well the only prob is this code has been showing since the end of last summer and if the 02 sensor was affecting this it would have started this last year wouldn't it?

 

Sounds like that seconds O2 sensor is bad, throwing the car into 'limp' mode as P stated. The car probably feels like it's missing when trying to go above 3800 rpms or so, and is probably running extremely rich when doing so, smelling strongly of unburned fuel, and maybe some black smoke. Sound about right?

 

Well the car is not smoking or has a rich gas smell. The car is running just like the day I bought it except after it runs for a while right at 3800 it surges and you can let off of the gas and it stops and continues running like there is nothing wrong.

Today for example it surged at 3800 when I went from a complete stop I let off and it stopped. I then stopped at the grocery store came back out and pulled out of the parking lot and floored the gas and it ran like a top with no problem. It is like it resets the problem when you turn it off and it cools down for a while and after getting warm again it is back.

 

The next step I took was I removed the battery cable yesterday and let it sit over night. Reconnected them this morning and again I got on the Interstate went two exits no problem. Then I turned around to come back and when I hit the ramp got on the Interstate and the tach hit 3800 the engine started surging again like it was hitting a rev limiter. While it is doing this I can let off the gas and then hit the gas again and it quits surging. While on the Interstate I can floor it and it is like the car goes to first gear and continues to slow down even when I have the gas all the way to the floor and holding it there then when I let off the gas it quits like nothing is going on.

The CEL started flashing and the codes are below. Could it be the throttle positioning sensor or mass air flow sensor causing this?

P1259 VTEC Mod (Has been replaced with new one)
P0303 Cylinder 3 Misfire Detected (plugs, wires, rotor cap, rotor button have been replaced)