I got a 2000 Camaro z28 43,000 miles it came completely stock only thing I did was install long tube headers y pipe, msd spark plug wires, and ngk spark plugs it worked fine when I threw them on till like a month ago my car started backfiring when I accelerate fast I changed the spark plug wires(too stock) got new spark plugs and changed out the knock sensor cause I have a obd2 bt scanner that said it might need swapped out but it still backfiring any clues too why it would be doing that? the picture shows what the obd scanner says also the long tube headers did take away 2 02 sensors so I kinda figured that what some codes are.

 

make sure you didnt burn a wire, you are using heat boots right? and if the o2s are really old put new ones in (good ones no amazon junk same goes for plugs/wires theres alota fakes out now that will cause problems) and last get a tune on that thing.

 

Well, did you have it tuned for the Headers?

If not, that's why you have a bunch of codes.

 

If it worked fine for an extended period of time and then suddenly started backfiring, then the header install itself was not the problem. A tune will make it run better and maximize the gains, but this isn't going to solve a problem that occurred long after the modification in question.

The two codes related to the front O2 sensors are the ones I would worry most about (P0132 & P0152), as well as the P0300. There are several things that could be causing all of this, but tuning isn't going to solve it if the problem took a long time (post header install) to develop.

 

I'm thinking the cold weather we have now is a factor but that's just me. Computer compensated for only so long..

 

Looks like an ignition problem, first and foremost. Hard to say what exactly, butt since you've been strafing it with the parts machine gun, I'd look over all that VERY carefully.

"Bank x Sensor 1" O2 sensors are the ones the ECM uses to get feedback on the mixture. Once the ign sys is working right, clear the codes and see if those come back.

"Bank x Sensor 2" O2 sensors are the ones that give info about catalyst efficiency. If you have no cats, they're not gonna be very efficient. Best to just tune those out.

Not sure how the knock sensors are reported. Clearly in a 2000 engine there's no "bank 1" and "bank 2" those since they're both in the intake valley, although scanner software might translate the codes that way, in which case, "bank 2" is likely to mean the rear one, assuming exact factory wiring. Again, that may sort itself out once the ign sys is working right.

 

Did you happen to use RTV on your gaskets? They can mess up your O2 sensors. It’s odd to have so many 02 sensor problems, for the rear sensors, did you use extensions and your stock sensors or swap to the corvette sensors? Will your scanner show what cylinder is misfiring where you could swap coils around to see if that’s the problem.

 

The only parts I replaced were spark plugs ngk they where from Amazon idk if that makes a difference I put the old wired on as nothing was wrong with em the msd ones didn’t seem burnt but some of the boots did have burn marks I also replaced the knock sensors and manifold gasket that’s what my scanner said might’ve been the issue this Tuesday I have an appointment with a mechanic and I’m gonna try and find a tuner to get a good tune any suggestions for the Michigan or Indiana area would be nice lol.

 

Ok, so the long tube headers took away 2 o2 sensors??? What I take away from this statement is that you've now eliminated the front o2 sensors...???

If so that would explain a lot.

 

There've been some low grade Xhinese counterfeit " NGK labelled" sparkplugs fouling the supply chain for a while now.
You might have defective spark plugs.
BUT, if you are trying to run closed loop, without a functional PAIR of narrowband O2 sensors, I'm not sure what to tell ya.

 

Do you mean that everything was fine immediately before you replaced the plugs? And then the issues started? If so, then you most likely either have a faulty plug(s) (or it got damaged during install, such as being dropped or using a swivel socket that caused a crack) and/or a wire/boot became damaged during removal or reinstallation.

I would not recommend getting it tuned in its current condition. Again, if it ran fine for quite some time after the header install, then the tune being somewhat "off" is not the problem here. Something new has happened, and it should be repaired before you have the car tuned. In fact, any good tuner will tell you this same thing.

I think he means that the REAR O2 sensors were deleted during the header install. At least, that was my takeaway from his statement. If so, this is normal and would have nothing to do with his issues.

 

Yea I believe it was the 2 o2 rear sensors I deleted and the wires and plugs I did swap them during the header swap for msd wires and ngk plugs the original ones didn’t have any issues I just decided to change them the where working just fine after the header swap it worked good for about 3 or 4 months then suddenly started backfiring on acceleration so that’s when I changed out the spark plugs and went back to the original plug wires swapped out the knock sensor cause my obd scanner suggested it and yea I was gonna get the car fixed then tune it I’ve just really had no time to take it as I work too much.

 

Backfiring or detonating?

This colder weather my C5 Z06 is running a little bit more fatter than normal, it's pretty much straight piped and pops in between shifts now, why I said what I said about the colder weather. I did my tune after the Headers when I installed them and it was much warmer out. Definitely no lack of power, lack of traction is there tho.

Car ran fine for 4 months and now you have issues, all of us know the weather is colder, your car is un-tuned and the PCM compensates only so much. Why that is my theory.