SES Codes>>Not Sure What to do

[mikriman1]

Had my QTP Headers/ORY on for a year now. The EgR codes were deleted and the car was tuned. I was at a red light today and the engine kind of puttered then the SES came on. I had the codes pulled and I'm getting a P0151 and P0174. I'm not sure where to start looking or what to do. 151=O2 sensor and 171=running too lean.

[keliente]

The bad o2 sensor is probably not reading correctly, and thus making the other code happen from an incorrect air/fuel ratio. See if you can look at the o2 with a scanner, it should be bouncing back and forth. If it is stationary or sticking one way or another, there's a problem. The coating on some of these headers fouls out the o2 sensors...or it might just be due to mileage/age of the car.

[2001NBMZ28]

Both codes are passenger side 02. If the connections look OK, and no burnt wires - probably just need to replace it.

[mikriman1]

Thanks for the info