I have a 1997 Z28 6Speed. It was bought used with 85k miles back in August. It now has about 96k. The previous owner had removed the cat, added magnaflow muffler. The service engine soon light is constantly illuminated. I have had the codes pulled to ensure that that was the only reason for the light, it was. With reasonable driving I get around 23 miles to the gallon.

My question is this:
I have been told that removing the cat= more power, I have heard that on these engines (w/OBDII) it means less power.

What is the truth? What exhaust configuration will produce the most power from open headers to stock etc...??

Does the engine light being on alter the overall performance of the engine? Will removing the o2 sensor and "hanging it" outside in the pipe in open air help?

There are many urban legends, but I am really looking for factual answers on the issue.

Thanks,
Matt

 

All you would have to do if you remove the cats is get the o2 simulators by Casper Electronics. Summit has them for less than $100. They are a plug and play design. They take the place of the oxygen sensors behind each convertor. You just unplug the oxygen sensors, and plug them in, and they tell the computer everything is ok, even if you have no cat. I had my SES light on and they worked for me! I have also heard that they increase HP a little bit....but I don't know if that's true or not. Good luck!

 

Removing the cats on a '96 and '97 will increase HP, unless you add some kind of weird flow problem with whatever you replace the cats with. The rear O2 sensors will turn the SES light on, but it does not effect power, fuel trim...

Like stated earlier. 02 sims will make the SES light go away, if the code you are throwing is for the rear 02's due to no cats.

Dan

 

Ok, I hace a 96 Z-28. I have one cat + that huge canister coming off the drivers side exhaust manifold. Do i also remove this?