Hi-Flow Cat for 2005 Cavalier

[Hyde552]

I have been told there is not an 02 sensor for the 05 cavalier but I have seen some people saying they have one with a hi-flow cat so can anyone bring about some truth. I was going to order one from RKsport and they told me there is no 02 sensor for this year so basically I will be throwing engine codes.

[cdru]

There should be one before and one after the cat if it's like every other ODBII vehicle I've worked on. The one after is used to gauge the efficiency of the cat and to detect a problem. It should be fairly easy to look after the cat to see something screwed into the exhaust pipe. The sensor is about the diameter of your tumb and may be screwed into the cat, or just after the cat into the actual tailpipe. The upstream sensor, the one the computer uses mainly, is somewhere between the cat and the engine, usually closer to the engine then the cat.

Note that your current factory cat should have a 8 year/80,000 mile warranty. Replacing it with an aftermarket cat will obviously void that part of your warranty. Have you done some type of performance upgrade to your system? If not, replacing that new of a cat probably wouldn't give you any noticable amount of performance increase.

[Hyde552]

Originally Posted by cdru

There should be one before and one after the cat if it's like every other ODBII vehicle I've worked on. The one after is used to gauge the efficiency of the cat and to detect a problem. It should be fairly easy to look after the cat to see something screwed into the exhaust pipe. The sensor is about the diameter of your tumb and may be screwed into the cat, or just after the cat into the actual tailpipe. The upstream sensor, the one the computer uses mainly, is somewhere between the cat and the engine, usually closer to the engine then the cat.

Note that your current factory cat should have a 8 year/80,000 mile warranty. Replacing it with an aftermarket cat will obviously void that part of your warranty. Have you done some type of performance upgrade to your system? If not, replacing that new of a cat probably wouldn't give you any noticable amount of performance increase.

how much horsepower would be gained putting on a hi-flow cat? if I can find one for an 05 cavalier and a 02 simulator to replace the factory so i can not throw any engine codes?

[Hyde552]

Originally Posted by Hyde552

how much horsepower would be gained putting on a hi-flow cat? if I can find one for an 05 cavalier and a 02 simulator to replace the factory so i can not throw any engine codes?

oh yeah forgot to mention I have added air intake and exhaust.

[cdru]

Depending on exactly what you've done, anywere from none to 10...maybe. More likely you would only see a couple if any. Just being hi flow doesn't add horsepower. If the stock system could "breath" easy to begin with, upgrading the system may not yield any performance increase.

Using an O2 simulator is against federal law for street use on polution controlled vehicles.

[Hyde552]

Originally Posted by cdru

Depending on exactly what you've done, anywere from none to 10...maybe. More likely you would only see a couple if any. Just being hi flow doesn't add horsepower. If the stock system could "breath" easy to begin with, upgrading the system may not yield any performance increase.

Using an O2 simulator is against federal law for street use on polution controlled vehicles.

Thanks for the advice, I know changing sensor out with an 02 simulator is legally wrong. but I was told thats the only way to keep from throwing up check engine lights if you change the cat. Is that true or false? I would like to change it but another problem is finding a website that has everything I need for an ecotec 05 cavalier.

[Mod'd_Cav]

i would forget about the cat dood...just use that money for something more productive..like plugs and wires...you'll notice more of a gain thru those then a cat...besides..like CDRU said..might as well stick with the warrenty

[cdru]

Originally Posted by Hyde552

Thanks for the advice, I know changing sensor out with an 02 simulator is legally wrong. but I was told thats the only way to keep from throwing up check engine lights if you change the cat. Is that true or false?

I would say that is false in my experience. I just replaced the cat in my 98 Montana. The old one was poisoned from a head gasket problem. I used a universal cat that fit, it wasn't specifically designed for my vehicle. That was about a month ago and my check engine light hasn't come on again.

Now obviously a Montana minivan is different then a Cavalier, and the emmission differences between a 98 and a 2005 are also going to be different. But that has just been my experience.