car sometimes gets a dead pedal feeling
05-16-2011, 11:33 AM
#1
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car sometimes gets a dead pedal feeling ive been runnin my car with my old tune in my sig.. now i have ls3 top end.. ive been running it and it seems to be runnin a little lean and has no base idle at all since i added the 90mm tb.. anyways this week it developed a problem where once it just starts warmin up and you rev it it will pop sputter and run like ****.. and the only code im getting out of it is the knock sensor 2 low frequency.. would that have that big of an impact on this problem im having? even when im going slow it will just stall out or when im just starting out it will spit sputter and then start runnin good at higher rpms
05-16-2011, 01:19 PM
#2
Flat peddle is either timing or air fuel.
Have you scanned when it goes flat?
Loosing a knock sensor will pull timing, but I think it is just -4 deg for a 98....enough for a brief stumble, but not enough to make the car feel flat.
If the car runs fine when it is cold, and this problem only starts when it is warming up, it is probably an O2 sensor. You can either replace the sensors or unplug both and see if the car runs okay. It will toss a code when you unplug them, but it will force the car to open loop and the running should straighten out if it is an O2 issue.
You can scan the O2 sensors and see if they are regularly switching about their 450 mV switching point. If one looks slow or is consistently staying high or low, it is probably a bad sensor.
Have you scanned when it goes flat?
Loosing a knock sensor will pull timing, but I think it is just -4 deg for a 98....enough for a brief stumble, but not enough to make the car feel flat.
If the car runs fine when it is cold, and this problem only starts when it is warming up, it is probably an O2 sensor. You can either replace the sensors or unplug both and see if the car runs okay. It will toss a code when you unplug them, but it will force the car to open loop and the running should straighten out if it is an O2 issue.
You can scan the O2 sensors and see if they are regularly switching about their 450 mV switching point. If one looks slow or is consistently staying high or low, it is probably a bad sensor.
