Emissions Help Please.

[nsweeney86]

So, as some of you may know, I recently purchased a 1997 mustang GT. Since than, I been working on fixing all the little issues and made it to the last one and im stumped. Maybe you stang veterans can help me out.

I am throwing 4 codes (P0136,P1152, P0161 and P0141) all of em have to do with oxygen sensors so I replaced all four. Thought for sure I fixed it, NOPE! Driving to work this morning and all four codes are back. Any.idea what could possibly cause this combonation of codes? Any information would be greatly appreciated. Thank you guys

 

[nsweeney86]

Been doing alot of research and got it narrowed down to a super clogged filter(new one on the way) and spark plugs. Just seems like its not getting the proper air/fuel ratio so its all jacked up. Lol runs decent but definately a lack of throttle response, random backfires and raw fuel smell. Ill let you all know how it goes. Thanks

 

[wmburns]

In this case. the most important DTC codes are the P0136 and P0141. These DTC codes call out a specific failure (Circuit malfunction). For a circuit malfunction think wiring fault (short/open), or other major circuit problem.

At the risk of stating the obvious, did you check the fuses?

Are you positive the O2 sensors are wired correctly? IE the kind of sensors with just a pig tail could be wired incorrectly.

Likely there is a wiring harness fault someone in the car. Especially since the O2 sensor are new?

>>from the Ford service manual
P0136 - HO2S Sensor Circuit Malfunction (HO2S-12)

• Pinched, shorted, and corroded wiring and pins.
• Crossed sensor wires.
• Exhaust leaks.
• Contaminated or damaged sensor.

 

[nsweeney86]

Hmm, to be honest I bought it very recently and the guy claims to have replaced all of the o2 sensors but they dont look to be very new. The only one that looks to be newer is actually hardwired. That is the driver side rear sensor. The rest look to be stock plugs. Guess im gonna have to jack this bad boy up, find and schematic and see we has/hasnt been done. Lol

 

[nsweeney86]

Hmm, to be honest I bought it very recently and the guy claims to have replaced all of the o2 sensors but they dont look to be very new. The only one that looks to be newer is actually hardwired. That is the driver side rear sensor. The rest look to be stock plugs. Guess im gonna have to jack this bad boy up, find and schematic and see we has/hasnt been done. Lol

 

[nsweeney86]

Also, i have checked the O2 fuse. Seemed to be good. When I got it, I didnt know it but the basterd pulled the check engine light out of the cluster. He lived in an area that dont require emissions and didnt mess with fixing that stuff. Seems to run fine just wont pass emissions with said codes lol

 

[nsweeney86]

Bank1 sensor two would be the passenger rear sensor, correct? I just crawled out from under there and wiring on all sensors look good but three of the four sensors look very old. Thinkin the guy only replaced bank 2 sensor 2 (driver rear) betting I have a crapped out sensor. Damn craigslist people lol