Hello JON, I have attached a copy of that technical service bulletin, it is only applicable to the 1997 model year, the programming issue would have already been installed on later model year vehicles. If you do have any pcm updates available for programming on your vehicle, you can expect to pay approximately one hour lablor to install it at the dealer, however if you ask them to verify the catalyst efficiency and check and install any available updades at the same time, there shouldn't be any additional charge and it should still be at approximately 1 hour labor at your dealers labor rate probably between $75. and $95 per hour. I have also attached a technical service bulletin that covers service tips for diagnosing oxygen sensor and catalyst monitor trouble codes for your review.
TSB 03-24-05 DOWNLOAD HERE
TSB 01-09-07 DOWNLOAD HERE
THank you SuperBob for the info.... I am confused a little because I just had the codes pulled for a " Mega parts house" with their code scanner. They list a few possiblilties such as: engine mis-fire, large vacuum leak, of oil leak into exhaust valve guide due to worn rings or seal.
I have also heard that a bad or clogged EGR valve or faulty DPFE sensor can cause these codes. They are fairly inexpensive and I was considering just cleaning and then testing the EGR with a vacuum pump to see if it is still free. I do plan on checking the vacuum hoses to the DPFE sensor since it is tied to the EGR.
Rather than just throw parts at the problem, I am trying to narrow down possiblities. Believe me I realize that short of having the car and a bank of computers to start the diagonsis, you are kinda limited with choices. Replacing an O2 sensor is not too bad a job - and while it may be a tempory fix, I am afraid it may not solve the problem long term. The parts store suggested I start with them.. makes sense because they sell them!
I will do what I can here short of taking it to the dealer. IF it does need new cats - any idea how much a cat will cost? will they replace one or both cats bank 2? Will they want to replace the O2 sensors at the same time?
Sorry for the additional questions. I am reading the 2nd TSB you sent me now. It should give me a general direction to go in.
The catalyst monitor code that was set is comparing the oxygen sensor data on the outlet side of the cat versus the oxygen sensor data on the inlet to tell if the catalyst is working well enough to extact the polutants from the exhaust, usually a fautly sensor would not cause this code but a different code. Odds are you will require a new set of cats for this side of the engine, a scan tool monitor can look at the data stream and check the other side too, to see how close it is to failing. The catalysts can fail in this way for various different reasons, if the engine had a misfire early on in life the extra unburnt fuel could have overheated it 20 or 30,000 miles ago and shortened its life, it could have an active misfire or sticking fuel injector allowing too much unburnt fuel down there now, you could have hit a rock or curb on the cat and caused external damage to it causing the catalyst material inside to fracture. The scan tool diagnostics will also look at the fuel trim to see if your pcm is commanding a higher fuel trim due to a incorrect sensor reading, for example, if the mass airflow sensor is dirty and not reading all of the air that is entering the engine, it will not add any fuel for the air it cannot see, after combustion the 02 sensors pick up that extra air and determine the mix is lean, it then trys to compensate by changing the fuel trim and running richer. The mix is not accurate and may add too much fuel, the changes afffect overall performance. The dealer is not always the first choice but aftermarket shops to not have the knowledge or tools sometimes to correctly fix all concerns. If you replace the cats, without finding out what caused the failure, you may have your new cats fail before too long. The last set of cats I did on a 4.6 liter ran about $800 per side, this was a couple years ago. You may be able to locate a local exhaust shop that can cut your old one off and install a satisfactory aftermarket replacement for much less.
Thak you SuperBob for the excellent reply. I printed off the TSB and was reading it while I waited for the reply. It sounds like I should go ahead and take it to a repair shop or a dealer I can trust (if I can find one).
I will print off the answer as well and take it to the shop to discuss with them. At least they will know I am trying to help without wasting my money.