Thread: Installed plog (and DP) and now issues! (w/vid)

My friend and I put on a ZZP plog the other day and for the most part everything seemed to go well. I drove the car around and it seemed fine. Then when I went to go give it some good throttle I got this weird backfiring sputtering going on. I've been suspecting that I've had a clogged cat for some time so I before I freaked out about it I went and had the 3" catted DP installed to see if the cat was the problem. After the DP install, it's doing the exact same thing. It idles just fine and if you drive it conservatively, you would never guess something was wrong.

In this vid you can see that if you take the RPMs to 4.5 is starts doing that sputtering thing. It seems like it just might be the rev limiter, but if I'm at a light and then pin it, it will do the same thing at lower RPMs (just not consistently like in the vid. It will sputter for a second and then move on). Similarly, if I'm on the freeway cruising along at 2 RPMs and then pin it the car will shift down, sputter a bit and then take off with no problem. I spoke to another friend and he suspects the coils are the cause, but I'm at a loss as to how putting in a plog could blow my coils!

Please take a look (listen) to the vid and let me know if you have any ideas at all! (If you have good computer speakers with decent bass range, you'll hear it better). Like I say, this could very well just be a video of the rev limiter working like it should but I don't know if I can effectively video whats going on while I'm driving. This is just to give you a sense of what I'm hearing when I put the engine under a heavier load.

Thank you!!

I'd look into ignition issues, I assume no SEL?

Maybe even a clogged fuel filter or maybe air filter?

No, no codes and the air and fuel filter were just changed recently.

Then I'd start looking at your ignition.

maybe burnt a plug wire on plog? id inspect wires.

is it loosing power at all?

thats the rev limiter try and do that in neutral should raise the rpms for the rev limit and see it is does it

THANK YOU for all the posts/suggestions guys - I really appreciate it!

Originally Posted by gtpinsc

maybe burnt a plug wire on plog? id inspect wires.

Originally Posted by Green97GTP

Im gonna say burnt plug wire on plog, Or firing order off?

I talked to another friend tonight about this and he suggested the same thing. He said the same thing happened to him when he replaced the LIM gasket. I will for sure check them out and will see what I can find. When we did the plog we did have to pull the front wires off to get them out of the way.

Originally Posted by chrisb

is it loosing power at all?

Eh, when it's doing the brief sputtering thing, yes. But once it stops, it's like the car goes back to complete normal and takes off like usual.

Originally Posted by TorqueAutoMotiv

thats the rev limiter try and do that in neutral should raise the rpms for the rev limit and see it is does it

Yeah, that's what I thought. I'll try your neutral suggestion and see what happens.


Thank you again to all for the input - very much appreciated. If anyone has any more thoughts or ideas in the meantime, feel free to shout them out. Thanks again!

firing order for front from left to right is 1,3,5 seemed to be running to smooth for firing order screwed up... id put money its a burnt plug wire.

Originally Posted by gtpinsc

firing order for front from left to right is 1,3,5 seemed to be running to smooth for firing order screwed up... id put money its a burnt plug wire.

With a bad wire you think it could still run smooth at times other than heavy load?

yes... my headers burnt #3 wire and it ran normal at idle... give it gas and it bogged down.

Originally Posted by SliceTheRice

With a bad wire you think it could still run smooth at times other than heavy load?

yea under heavy load theres more current so if it is burnt at idle its not arching but under heavy accel it would arch hard and draw current away from plug

Sweet guys, thanks! I'm going to take a look at the wires tomorrow and see if I can't get to the bottom of this. I'll update later. Thanks again!

Ok, so yesterday I went out and messed around with the front set of wires before taking it for a long drive. I drove it for quite some time and it STOPPED DOING THAT STUPID SPUTTERING THING! It drove great for about a good hour and then on the way home it started doing it again. So later I did a closer inspection of those wires, looked for burns, external damage or wear, and I couldn't find any. I put them back on and tried to make sure they weren't touching anything (as much as possible anyway) and then drove it around some more last night. No hiccups. Then on the way to work (abt 45 minute drive) it didn't do anything stupid either.

So I'm going to keep my eye on it, but fooling around with the wires definitely made a difference.

How about getting new wires? You can get the Autozone lifetime Duralast wires for like $30.

I probably should, huh. Yeah, I probably will. Just to be safe.

And they are lifetime warranty too...so anytime you fubar one...you can bring them in and exchange them for a good set.