PO326 Knock sensor

While it is possible, it is not likely that CAT is plugged on your

----------------- TheSnoMan.com

Be sure to price-around for aftermarket cat.converters - IF that is what the trouble REALLY IS. It is seldom the case, these days. Good luck. Let us all know how it turns out. JT

You must have a lot of miles on your 2002 car for it not to be covered under an emissions warranty.

Are you subject to emissions testing where you live?

Where I live has recently dropped the testing. We went to a reformulated gasoline. Before then, all aftermarket converters would not allow the car to pass. You get what you pay for. If you buy aftermarket, be sure to get the facts if the car will still not pass.

James

There are other tests for a blocked cat that should be performed before laying out that kind of money. If they don't want to test before replacing expensive parts, I think I'd go get another opinion. I can't see how you could conclude that the cat is bad with the P0326 code, especially if that's the only code. The service manual for my '97 Saturn lists these as possible causes for P0326: Valve Lifter Noise, Belt Tensioner Noise, Loose Brackets, Cheap gas, Scuffed Cylinders. The system tries to correct noises the knock sensor hears by retarding spark. If it can't eliminate the noise by retarding, it sets the code.

RK Henry

Good tips, CAT's rarely plug up and when they do it is usually on a engine that has been running poorly for a long while too. I have yet to have one personally and I have run some past 200K and they still passed emissions too.

----------------- TheSnoMan.com

Henry 's post mentions cheap gas as a cause of this code and you say you just changed to reformulated gas! Can you still get regular gas and try resetting the code? If it is the cause it should go away after two tanks.