I don't know if this is the correct place to ask this since it says for new LS1 owners.
Anyways, not to long ago I got a 93 Z28 m6 and it runs good for the most part. However it seems to be running rich, because at idle I can smell a gas like smell, plus when I let off the gas I get a sort of crackling noise from the exhaust which I'm assuming is unburnt gas in the exhaust. I currently get about 170 miles out one tank of gas.
Does anyone have any suggestions? What could be causing all of these symtoms and how to fix them?

 

Do you have mods?? Do you have an aftermarket tune?

 

Bad o2 sensors can cause it to run rich...

 

As far as mods go I know it has a flowmaster muffler and thats it. Someone I know says it might be cammed but he isn't sure. I kinda doubt that it is. I don't think it has a performance tune either.
I was thinking it could be the o2 sensors as well...how much would it cost to replace those?

 

my bet would be the o2 sensors

 

I agree with the members up top. Bad O2 sensors are usually the first to blame. As far as fixing it, hook up a code scanner and see if the car throws O2 numbers. If you dont have a scanner, you can go to any local parts store and ask them to scan the car for you.

If your O2 sensors are in fact bad, buy some new ones and replace. I dont know your financial situation, but If you dont have the cash right now, you may be able to check for used, low milage O2 sensors here on the forum as a temporary fix untill you can afford new ones.

Here is the link for Autozone O2 sensors, i entered your model and year, so these are correct for your car.

http://www.autozone.com/autozone/par...nsor/_/N-9ixrp

Hope that helps.

 

IMO AC Delco is the only 02 sensor worth getting. Bosch, Denso, etc are all junk and break quickly. You pay more for the AC Delco but in the long run its worth it.

 

I cant comment much on the brands because i havent had to replace mine yet..knocking on wood..lol.

 

Ive ran bosch with no problems. They are usually warranted to.

 

Thanks for the help guys
also does running rich tend to make the engine bog down? When I accelerate it seems to be a bit sluggish at first until the rpm's pick up.

 

yeah bad o2's can make it run like **** as you described

 

Please scan the car before you spend money on it. since its a 93 you can scan it with a paperclip.