Skillz

I have a 99 Si, stock engine still with a drag turbo kit on it. Running with FMU and Inline fuel pump. The car runs fine. The only problem is about after 2 weeks of running the engine light came on and it was code 61 (primary O2 sensor). I have to do a little more research but is it possible that my car is running too rich due to the FMU (12 : 1 disk) and inline fuel pump and threw the code? I also have the fuel pump power wire and A/F gauge power wire spliced into the same wire under my hood, there is a bundle of wires on the driver's side that go to a connector. I spliced them into the black wire with yellow stripe on the front side of the connector (rear being closer to the inside of the car). I was wondering maybe this is the O2 wire (just a coincidence) and I spliced two power wires into it and maybe it is lowering the voltage to the O2 sensor and could be throwing a code. Any help or suggestions would be greatly appreciated.

Thanks in advance.

bye

are you just throwing a code or is the car acting up due to this code?

Skillz

From what I understand I am in limp mode when the car throws a code for the O2 sensor, and that means the car will not perform as well as if there was no code, correct?

bye

i was throwing an o2 sensor code but i drove fine, the only difference i saw was like 10 less miles on my tank of gas, now im throwing a too rich/too lean code, im assuming its cuz of my fuel pump/fmu

ScrewD03

that is true... so what is the code just primary O2 sensor thats it... nothing like heater failure or what??? So are you sure that is the code??? can you give the generic code then I might be able to help you... and I'm thinking the code might be P0133

NIC668

O2 code should not put you ecu into limp mode. Limp mode is more when something like a map sensor goes bad I could be wrong correct me if I am.


Check the wiring.....The o2 could be bad...I mean how many miles are on the car? It is recomened you change the o2 at 50,000 and if your boosted I would change it just to be sure.

Skillz

Ok I checked the code about a week ago and it was O2 low voltage/slow response so I reset my ECU by pulling the negative terminal. A few days after that the CEL came back on...I assumed it was the same code again but as of tonight I found it was my speed sensor, my mechanic brought home a scantool and we checked it out and no O2 this time, I was wrong to just assume. But he was telling me even with the speed sensor code it will put the ECU into limp mode. After we cleared the CEL the car slowly began coming down...and the fuel trims were back to around normal. Thanks again for the replys though.

Skillz

Oh yeah...and as for the O2 sensor code....it may have been due to my exhaust hitting my shift linkage and rattling ALOT all the time. I fixed that and now there is no more O2 code so that could of been what triggered it. I heard the O2 sensor is very sensitive and a lot of vibration (shift linkage against the cat) could trigger a code.

ScrewD03

for that specific car yes O2 is very sensitive...