How can I clear the engine service light

[ewill3rd]

Angus,
You'll get better luck starting a new topic of your own.

However.... you need a throttle body and two catalytic converters.
Ouch! That is a lot of miles for an '05

[Angus Young]

Are the cats and the throttle body dealer items only? or is there aftermarket solutions available, I see there are no headers made for the 4.6 and as far as I can tell the entire exhaust manifold must be replaced. Also the throttle body, according to replys listed here in this thread that usually doesnt fix the problem permanently, and the reason I am reasking is my warrenty is clearly expired and this would be an out of pocket venture, the dealer quoted me $1900.00 for the cats, and are you aware of a aftermarket throttle body I can consider?
Thanks for your response!

[mike sts]

My car had both cats replaced also. codes came back. The last time it went in they looked again must have been the 10th time for air leaks and they found a air leak tech said he tighed all the hoses and fixed the leak the codes has been gone for 10,000 miles. It seems even small difficult to find air leaks can cause these cars to run lean. The final verdict for me was 15 trips to the dealer for this. The tech states the car definetly needed a maf and pcm, not sure about all the other parts they put in. I would say the cheepest place to start would probably be checking for and fixing any possible air leaks. Problem is you will need a very good tech, my experience with 2 different dealers was that the techs missed these air leaks 14 times and they stated they checked for them every time. One other tech near the begining of this found and fixed a air leak, he must have missed the other. Hope this helps. If you go through what I went through your looking at thousands on parts

[mike sts]

for parts I would go to GM parts direct or another online source you will save 40 to 50 %, most non dealer repair shops will install parts you bring to them especially if they are new factory. After all when they accept after maret warranty's these company's ship them parts many times to save money

[mike sts]

Ewill would know this better than I but if your car is running lean this can trigger catalyst codes because the cat is sensing impropper fuel and exuast levels and tries to correct. it will trow many other codes as well because the various sensors and computers are sensing and trying to adjust for this.

[ewill3rd]

On the V8 longitudinal N* engine the throttle bodies seem to be an issue.
The P1101 and P0068 indicate that the throttle body is not operating properly causing an airflow issue which will in turn set lean codes.
Other codes aside the P0420 and P0430 indicate that the converters are not working properly.

I don't know of any aftermarket parts available but I don't watch the aftermarket very closely. You'd have to do some searching or hope someone on here has seen that.
As I stated, you might start a new thread and outline questions that you have remaining.

If this is a V8 (which I suspect it is) the converters are going to be hard to find because they are actually part of the exhaust manifold, and a bear to replace.