I bet his wideband 02 sensor is on the cat itself. verify the sensors are in the right place.

 

thanks for the advice junky ill try that.

benes, no i made sure the wide band is on the headers. The shop did have to weld on a bung on the cat before the honey comb for 1 O2 sensor and used the original slot for the 2nd O2 sensor. Do you think the first O2 sensor is in the wrong place? The test pipe had 2 slots for the O2 sensors.

thanks again for the help guys

 

Your current set up with cat should be stock as mentioned with primary sensor at the header collector(closet to engine) and the secondary at the cat or TP. The additional sensor for the wideband should go somewhere between the two sensors when possible. Verify that this is the case. If the wideband senor location moved when swapping from TP to cat or vice versa, then it will provide a different reading, how much will depend on how much different the location is. Closer to the tail pipe will read leaner then closer to the engine where it will show richer. Closest to the engine is the most accurate, placing at the header collector or pre cat.

If the 02 sensor is tied into the tune (vie 02 feedback) then your tune will be effected by the new location of the wideband sensor, if the wideband is run completely independent and used just for monitoring then location wont have any effect on tune, it will just show a slightly leaner/richer number.