lt1 running rich

[camo95]

My 95 camaro is running way rich! I go to the track and everyone keeps telling a big puff of black smoke comes out the tail pipe. It does it all the time. I know its definetly fuel because a friend was behind me once when it happen and he said all he could smell was fuel. I put new o2 sensors in, but didn't fix problem. I have slp headers and had to cut O2 sensor wires and lengthen the wires to reach new O2 location. Don't know if this has something to do with problem?

[Joe 1320]

Re: lt1 running rich

Originally posted by camo95
I have slp headers and had to cut O2 sensor wires and lengthen the wires to reach new O2 location. Don't know if this has something to do with problem?

First, never cut and lengthen the 02 sensor wires. You have ultimately changed the resistance of the sensor by doing so and skewed the 02 readings. Lengthen the main harness prior to the sensor connector.

Second, any leaks in the header prior to the 02 sensor will cause a false lean, the computer will add fuel to compensate.

could be either or both of the above.

[camo95]

I lengthen the wires on the main wire harness side, not the actual O2 sensor wires. I have checked for exhaust leakes and couldn't find any.

[Injuneer]

It seems like "home brew" extensions cause a lot of problems. Remember, the O2 sensor output signal is in milliVolts.... 1/1,000th's of a volt. A poor splice it going to cause problems.

But you don't have to guess. Get a scanner on it and check the long term fuel corrections in a broad range of "Cells".... and in particular Cell 15. That will tell you if something has skewed the long term corrections to the point they are adding fuel you don't need at WOT.

Do you also smell fuel at idle and low speed/part throttle driving? Has your fuel mileage fallen off?

Did the problem exist BEFORE the header install and O2 sensor extensions?