OK, this may be a stupid question, but once again I can't find the answer. Which Catalytic Converter is recommended for a 2003 Bonneville SSEi? I am thinking of going with the Magnaflow, and I am not sure if I am right, but I was thinking of the Universal model with one sensor port, and 2.5 inches. Is this right? Or do I need 2.25 inches? Thanks again for the help!

If your car has less than 80k miles, you can get your CC replaced for free at the Pontiac dealership. They unbolt the exhaust from the motor and replace the whole exhast, CC, pipes, muffler and all. Unless you're just replacing it for the fun of it.....

I just replaced mine on my 2000 SE with the Magnaflow 94836. I got it on EBAY for cheep, it already has the O2 bung welded in. It sounds great with the factory Bassani muffler and the resonator removed.

2.5 along with a PCM or rear o2 simulator.

BoneZ- I wish. I have about 133,000 on it. It actually started throwing codes around 95,000. Now it is rattling and effecting performance. Gotta go I guess ...

USCGElectrotech- Is that version high flow? Or more of a standard CC?

Hans- thanks. Wasn't sure on the 2.5. What does PCM stand for? (Am I being dense?)

I am thinking of going with the Universal Fit high-flow 94136. It has the O2 sensor port in it, 2.5" tubing, etc.

Thanks for the help guys! I appreciate it.

That is the high flow version. I got it for $80 from Preformancepeddler on EBAY, they were great. If you have any questions about it just call or e-mail Magnaflow. Their Cats are made by a company called Car Sound, here is their web address http://www.car-sound.com/ I picked up about 5MPG with this cat and a K&N filter.

Jeek...PCM is the Powertrain Control Module aka computer. Spuds (aka Hans) was merely firing his potato gun in your thread.

There'* no reason why changing a catalytic should cause you to spend more money on programming the PCM to remove the rear O2 sensor or buy a simulator that acts like an O2 without having one.