I have a 1997 NA.

About a week and a half ago, my CEL came on. The car ran fine but after i scanned the car with the OBD2 reader it read the code p0140. The common issue associated with that code would be a bad secondary o2 sensor.

Assuming that the o2 sensor just needed to be replaced I drove the car as is for about a week until Friday when my indicators, reverse lights, tachometer, oil gauge, temp gauge and the warning lights for the cluster stopped working. Rescanned the car and p0140, p0135 and p0141 codes were showing.

I cleaned the ground wire below the master cylinder and replaced the METER fuse. Everything worked fine on the car and no CEL was on as i drove the car. but after i had turned the car off and turned it back on all the problems came back.

Im thinking that theres a short somewhere in the system. possibly a bad ground wire somewhere?

if you guys could help answer the following questions that would be great.
1. What do you guys think it is?
2. Which grounding points should i be inspecting?
3. Any other suggestions on how i can fix this?
4. The car is my only way of transportation, can i still commute with it while i try to fix it?

thanks for your help in advance!

 

have you fooled with your transmission lately?

 

only thing transmission related would be hammering in the tunnel to fit my bucket seat bracket. hammering was performed about a week and about 200 miles of driving before the problems occurred.

 

changes you broke reverse light wiring?

 

ill take of the carpet tomorrow and ill take a look at the wiring under the seat. now that i think about it, my hammering and the PCI v2 bracket might have interfered with the harness/ground for the secondary o2 sensor.

 

that would do it.