My car is a 94 Z28. The engine is stock with the exception of a CAI. I have a aftermarket muffer, but other than that, the exhaust is stock also.

Here's my question. Do you think it would be worth the money to get new 02 sensors, and a new cat (probably Random Tech)?

I don't race the car, I'm just trying to keep is running as good as possible.

Also, it's got 93,000 miles on it and to date, it still runs great.

Thanks for any opinions.

 

O2 sensors should be replaced about every 100K, but as long as the cat isnt clogged Id leave it alone, or if you dont have emissions, gut it or take it off.

 

Is your car running rich? idle problem? If it's running fine I wouldn't change them at all. Ever heard don't mess with it unless it's broken.

Vinny

 

The car actually runs great. I'm just going through and doing preventive maintainence.

Maybe a stupid question, but how could I tell if it was running rich?

would bad/worn 02 sensors have an effect on that?

 

If you're running rich you'd be able to smell gas in the exhaust and probably under the hood and maybe notice a slight stumble/hesitation at idle. O2 sensors are normally the cause of running rich.

 

Thanks

 

I've been told that bad O2 sensors can cause the car to burn oil, run sluggish and decrease mileage. Is there any truth to this?

Also, how often should the cat be replaced? Mine's going on 123,000 miles. Is there any plain and simple way to tell if it's clogged or going bad?

 

Bad O2 sensors can cause your car to run sluggish and it can decrease your mileage due to running rich (sensor is telling the PCM to use more fuel). Ive never heard about it burning oil and dont know how thats possible. As far as the Cat, there is no way to check it. If your car backfires alot and when you mash the gas it doesnt want to go its probably time to replace it, but a cat should last you almost the lifetime of the car(over 150K) before needing replacement, unless its been running rich for a while.

 

another way to test a converter is a temp test from inlet to outlet. All muffler shops will do this test, that's how they know if a cat is cloged up.

Vinny