2000 GTP - Finally Happened

That's right, ladies and gentlemen. I believe my cheapo headers / downpipe package from Pacesetter did me in. I turned the car over to a shop an hour ago. I have no faith in them. Only shop in the college area :frown:

Problem: Very rough idle (occassionally dies when idling). Louder-than-normal exhaust tone (can be heard from under the car). I was unable to pinpoint the exact leak(s) myself.
Also, the car slightly jerks (barely noticable) when driving. This is a newly developing problem. I felt one seriously jolt; it felt like it came directly from the two-year old tranny.

Solutions: (1) Find and fix exhaust leaks. (2) Replace front O2 sensor. (3) Find and fix vacuum leaks. (4) Sell.

Painful Truths: Previous owner didn't properly secure the 3.4" modular pulley. He also had the car tuned for a 3.2" pulley. He didn't tune the car for the ZZP XP-Hotcam :rolleyes:
So what happened when I was stuck in college with a shredded pulley? I installed the only extra pulley I had -- a 3.0" pulley and belt. (This was four months ago; I don't drive the car too much in college). I used that pulley because I was short on cash at the time. I wanted to wait until the summer to install it & an intercooler while the PCM was being sent in to be retuned. Luckily, the car was running beautifully with the 3" pulley, but I never was hard on the gas while it was in there. I knew the risks of running a pulley like that, without the car being tuned.

I'm keeping my fingers crossed. I don't trust the shop to fix my idle problems. I even supplied them with extra Autolite 103's & a new 3.4" pulley w/ belt...just in case they felt that changing spark plugs would cure cancer :screwy:

So is this just a rant or are you looking for advice or simply morale type support?

So you really think the Pacesetter headers are the cause? I don't care what brand you have whether TOG, SLP, S&S, etc. they all have their drawbacks and quality issues. Leaks are not uncommon especially at welded portions. Some are caused by poor installation when first installed. Start by finding and fixing the possible exhaust leak. Also, what are you using to monitor possible detonation and knock retard (KR)?

My apologies. I was meaning to look for opinions on other possible causes. I accidentally omitted that paragraph.
I normally borrow a friends scanner. While the problems were occuring, my KR would vary greatly. Some days would produce 4 KR, while others would invoke the wrath of 7-9. I drove the car very little when this happened consistently.
Being in college, I don't have access to nearly as many tools as I had when I lived in my hometown -- in my own apartment. I finally decided to drive it into the shop yesterday. They found the following problems using their equipment:
(1) Malfunctioning Mass Airflow Sensor -- I told them to leave it. I cleaned it myself today. That problem is gone.
(2) Faulty O2 Sensor -- Replaced.
(3) Significant Leaks in Pre-Cat Exhaust -- The headers were installed in the summer. Being that I live in Minnesota, the constant temperature changes put enough stress on the metal to worsen the initial leaks. The shop removed the y-pipe and downpipe to seal them with a cement compound.
(4) Melted Sparkplug Wire (possibly unrelated) -- One of the ties came loose and allowed a wire to come in direct contact with the new exhaust headers.

Before (Symptoms): Powerlag at high RPMs (looked as though the car refused to accelerate). This eventually worsened, then lead to a horrible idle and occasional misfires.

After: 1-2 KR. No problems. I still plan on sending in the PCM to be retuned when the opportunity presents itself (hopefully soon).

Shop Funnies:
quote: "Those Autolites are for a Ford vehicle. You should send those back to get a refund." - shop owner in reference to the spare set of Autolite 104's in my back seat (before repairs conducted).

quote: "My mechanic would like to keep the car for another night. He promises to fill the tank." -- shop owner (after repairs). Of course, I denied.

Intent: I wanted to post this on Automotive forums for feedback; also, I wanted others to have some sort of reference for future symptoms or problems. Of course, if I offended anyone with this post, as it did not present a direct question, I will understand if it is removed from the forums. Thanks everyone for your time :)

So is the car repaired? What was the final problem/fix?

So is the car repaired? What was the final problem/fix?



(1) Malfunctioning Mass Airflow Sensor -- I told them to leave it. I cleaned it myself today. That problem is gone.
(2) Faulty O2 Sensor -- Replaced.
(3) Significant Leaks in Pre-Cat Exhaust -- The headers were installed in the summer. Being that I live in Minnesota, the constant temperature changes put enough stress on the metal to worsen the initial leaks. The shop removed the y-pipe and downpipe to seal them with a cement compound.
(4) Melted Sparkplug Wire (possibly unrelated) -- One of the ties came loose and allowed a wire to come in direct contact with the new exhaust headers.


I believe the O2 sensor made the largest impact; though, all the other problems didn't help the situation at all. Bad / inconsistent idle + unwillingness to accelerate at high RPMs (car fights against you -- computer attempts to constantly adjust air / fuel ratio) = bad O2 sensor and/or dirty MAF sensor. This problem is fixed.:)

good to hear the 3800 didnt self destruct. better keep an eye on KR with the 3.0 pulley.