Ok this is what ive got. '96 2.4L cavi with HO mani swap, pacesetter header with 2.5" all the way back with no cat, and a few other lil things like underdrive pulley and so on. shortly after having the exhaust installed my car started running like crap. initial startup was no problem but when i would try to accelerate the car would bog down and wouldnt go even if i floored it. also when running at idle the rpm would fall to like 300-400 and sometimes go back and forth between like 300-1000 which most of the time if i just let it sit there and idle it would eventually die. i figured out that if i rev it up to about 3500 rpm then let the clutch out i could get it going and it would be fine. also i threw 2 cel codes. 1st was a knock sensor and the other was the aux emissions which im assuming is the 2nd O2. now this is my theory and i just want some help to make sure im on the right track.
not having a cat im assuming that the 2nd O2 is trying to lean out my a/f since there is no correction being made on the exhaust which is making my car run lean (so says the trusty a/f guage) which is in turn im assuming causing a bit of knock so the knock sensor is retarding my timing which is just leading to a crappy running car.
my question is if i get the O2 sim from casper electronics will that fix my whole problem? or is there more to this problem than i know???
any help here will be greatly appreciated.
why get an O2 sim, and just a normal O2 sensor?
Fact 1:
“Facts are meaningless. You could use facts to prove anything that’s even remotely
true.
that confused me... the O2 sim is for the aux O2 correct? which is the one that normally goes after the cat (which i dont have) so dont i need an O2 sim to make the ecm think i have a cat?
The second O2 sensor only tells the computer if the Cat is working or not, it has no effect on the fuel mixture. The primary O2 sensor controls the fuel mixture. The O2 Sim is used for making the PCM think it's seeing a Cat that is working properly, so that the PCM doesn't throw the code for the Cat/2nd O2.
The knock sensor is where the problem is arising from. With the changes you've done you are getting more air into the engine. You could be running lean, because of the injectors being dirty(very likely due to age), low fuel pressure(fuel pump or FPR) or even carbon build up in the combustion chamber, raising the static CR. I would start by changing the fuel filter if you haven't done so lately. Next check the fuel pressure. If the pressure is good look at getting the injectors cleaned and tested(I used
http://www.theinjectorperfector.net, good rates and quick turn-around), it wont hurt to have them cleaned anyways, especially if they are the original injectors. If the pressure was low then check the FPR and the pump.
madjack,
thanks for your help. im actually getting an adj fpr today and when i do so im gonna clean the injectors real good.... thanks for your help!!!
chris
