new parts now car running rich please help

[D's 91 stang gt]

Alright need some major help I recently put on a off road x-pipe and mac cat back and had the smog pump removed and now the car runs really rich I mean it just plain stinks bad I took it to a shop where the put on a fuel pressure regualtor and did a tune for it that worked a little but it still runs rich I don't know what's causing it but I want it fixed I was thinking that it could be a bad mass air sensor?? I read a while back that the cl 76mm was giving guys trouble making the car run rich I have one on my car but it never ran like this untill I had the exhaust put on. Any input or suggestions you guys have to help me will be apprecaited
thanks

 

[jtfairlane]

Are you running 02 sensors in your Off-Road x pipe? Did you use anti-seize on the threads when you installed them? This is a long shot, but if you used anti-seize that is not approved for 02 sensors (there are types just for that purpose), it can throw the 02s out of whack, which might make your motor run rich if the 02 readings are off.

 

[D's 91 stang gt]

yeah I have the o2 and they are hooked up but still runs rich

 

[jrichker]

Dump the codes and see what the computer says is wrong… Codes can be present without setting the Check Engine Light.

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.mustangworks.com/articles/electronics/eec-iv_codes.html

IF your car is an 86-88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 86-88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart.

Or for a nicer scanner see http://www.midwayautosupply.com/detailedproductdescription.asp?3829 – It has a 3 digit LCD display so that you don’t have to count flashes or beeps.. Cost is $35.

WalMart may have the above LCD display scanner for less than $35.

Bad O2 sensors will set codes 41/91.

 

[vristang]

^^^^^What he said


Also,
You have removed the cats, so any unburned fuel is going straight out the tail pipe.

Cats will make the car smell better.

Pull the codes and see what you get.


jason