Alright, so I installed my pacesetter header, magnaflow cat, resonator and cat-back yesterday and have run into some trouble. After a few minutes of driving I got a cel and the car started running like crap. It feels like the car doesn't know when to shift or when to actually feed gas to the engine. When you press the gas it doesn't always start accelerating, but then a few seconds later it will catch up to itself which will throw you back in the seat. Anyway, I'm thinking it's one of the oxygen sensors gone bad. I'd take it to Autozone or somewhere to get it checked, but the last time I went to try and get codes read every place told me my diagnostics port wasn't getting power so there was nothing they could do. So any thoughts or suggestions here? I'm praying it's not the sensor in the header because I don't know if I can handle trying to get down there again
. Oh, it's an 2002 Z24 by the way. Thanks for your help.
sounds like a o2 sensor to me prob in the header like you said i dont think you have a o2 in the cat so probley the header 02 if you added more wire to it make it longer make sure it smaking a good connection
well there is a sensor right after the cat. that's the one that looks old, but i did have to extend the wires for the one in the header so it could be a connection problem. we'll find out soon.
the o2 sensor after the cat is for catalyst efficiency only. it tells you how well you cat is working. most people with aftermarket exhaust usually run in to this problem because your exhaust now flows to much and your cat can not work efficient enough. the one on the header is the sensor for air/feul.
well i put a high flow cat from magnaflow on. i dont have the stock cat on anymore. i checked the wiring that we put in to extend it long enough to reach the header, so i guess the sensor just went or something. otherwise im out of ideas.
you didnt need to extend the wires for the o2
you just needed to take the plug off the bracket it is on and they will reach each other
if you were watching when you were adding wire to it you might have crossed the 2 wires , or you have a bad connection
hmm. i took it off the clip and got as much wire as i could and it still didn't reach. but anyway, after messing with those wires i went for a drive. the cel is still on but the trac off light turned off and the car is running fine now. so im not sure what's up. perhaps that's just because of the exhaust flowing so much better now? im going to chevy tomorrow to tell them about the diagnostics port not having power since the car is still under warranty. it's too frigan frustrating trying to guess what the cel engine light is from.
Which Magmaflow High flow cat did you use?
Cause one works well and one doesnt.
Hmm, I got it from TurboTech Racing. The SKU number was MGF94035. 2 1/4 inlet and outlet.
on my 00 all i did was took it off the bracket it was on and there was plenty to reach
maybe re-routing the way the plugs sit woulda helped , since they are in a bundle of a rats nest , lol
if you kinda played with the wires and it cleared up , i bet you have a bad connection some where
ive got the 91305 or something cat , and no codes , i did both the header and cat at the same time
i dunno, it's weird. at least the car is running fine now. it was creepy to press on the gas and have almost nothing happen for a second and then all of sudden it feels like you just floor it. the header definately helped the car out. though this thing is raspier than i ever imagined.
The CEL might be coming on if you lengthed or changed the gauge of the wires connecting to the before cat O2 sensor. They are a certain length that provides a certain resistance to the O2 sensor. If you lengthed them or changed anything about them they are probably what is triggering the CEL the computer thinks something is wrong since the resistance has changed in the wire.
Im using a MPE-94035 when i redid my exhaust, no codes so far, though when i did mine, i put in 2 new 02 sensors. I call it piece of mind.
When I did my header about 4 or 5 month later the car started doing the same thing and running rich as hell. The problem for mine was the car was basiclly flooding out, over loading what ever you want to call it. I replaced the o2 sensor didn't cut the wire just striped the harness and keep pulling wire out. It will eventually reach, but it run fine now except for the #2 sensor now.
I am running the same header and cat combo(except its an eco) and I haven't had any problems. Did you rest your computer? If you don't have a code scanner, go to autozone and find out what code it is.
2012 HD VRSCF
2010 Ford Explorer
2006 Ford Ranger
2004 Chevy Cavalier
Like I said above, I can't get the codes read because my diagnostics port isn't getting any power or something. Going to Chevy to get that fixed tomorrow. Anyway, things magically seemed to work themselves out. The Trac Off light turned off first and the car started running perfectly fine. Then some time later the cel finally turned off and was good for about 5 hours of driving. About an hour ago the Trac Off light came back on, but the car is running alright, but not as well as it could. So I'm at a loss now. We'll see what tomorrow brings.
i would make a bet on something with that first sensor being bad. as vaguely hit on above, if you want to try and diagnose it w/o the cpu, the first thing you need to do is make sure that primary o2 sensor is working. the sensor itself could be bad or it is your extension of the wiring. you dindnt touch the part of the sensor that sticks in your exhaust pipe did you?
Check all the fuses before wasting your time taking it to the dealer.
michael groves wrote:i would make a bet on something with that first sensor being bad. as vaguely hit on above, if you want to try and diagnose it w/o the cpu, the first thing you need to do is make sure that primary o2 sensor is working. the sensor itself could be bad or it is your extension of the wiring. you dindnt touch the part of the sensor that sticks in your exhaust pipe did you?
Yah, I touched it and wiped it with a semi clean rag. Also shot some PB Blaster before I removed it to make sure it would come out. I know this is a very old thread but with a new header and exhaust I too am getting that trac off light. I did not think the rear O2 would cause a lean open loop problem. Is my rear O2 fubared? Just came on this morning on the way to work so I won't get scanned until tonight. Any thoughts?
Labrat
from the sounds of your problems and your car is a auto,it would lead me to the IAT sensor in your air intake..But i could be wrong..
Thanks Jason, Since I haven't really talked much about my car it is a 5 speed with a GMSC. I installed a Pacesteer header and 2 1/4 exhaust with a GTO muffler welded on. I certainly will check the IAT but my I am rarely that lucky. Thanks for the help though.
Labrat
Got gas on the way home and when I restarted the car the light was off. Gonna get scanned to find out if there is a pending code but so far so good.
Labrat
hmmmm ok,I looked up the car in the very first post that was made...So if its a 5 speed wont be a IAT..When I installed my pacesetter I had to change the 02 sensor in the header,But I when it was bad never ran like what you are explaining...
but I also have never seen a trac light on a 5 speed,only on a Auto???
Bringing back a 4, almost 5 year old post = retarded. Thread jacking a 4, almost 5 year old post (that isn't even for the same car!) = completely asinine. Just search, and if you have to, make a new post.
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