I have a 97 Tahoe with 66,000 miles on it and have had no problems with until now. I recently had my service engine soon light coming on for a couple days then it would go off. I hooked it up to the computer and it gave me two different codes, the first one was PO 141 and the second was PO161. Both of them are O2 sensors after the cat codes. I didn't know which one I should replace first or just do both of them at once. Has any one else had this problem and if so what do you suggest? Thanks for any help

for the heaters in both to die at once is uncommon, but it does happen. if you have access to a schematic would double check that the circuits are not "related". if no schematic aailable, crawl under there and check the wires for both sensors, if looks ok, would just replace sensors. research cost for both sensors(if doing yourself), and cost of the diag fee at local shop of choice. best of luck

The O2 heater circuit (power and ground) are the same for all 4 O2 sensors. However the inputs to the VCM from each O2 sensor are all separate. Hope this helps..........Steve

the fuses should be checked i believe EMI fuse , the o2 sensor internally can be intermittently shorting out heater circuit causing both to create po 141 & p0161. are you sure vehicle has 66,000mi? wires/connector could be damaged, or exhaust/ manifold leak