Contour Enthusiasts Group Archives Forums General Troubleshooting Please advise before something......(code 176)

else goes wrong or gets damaged. i have a 95 se mtx. I am getting code 176 bank 2 running lean. I have replaced the o2 sensor with a brand new one from bosch and still the same [censored]. The one i had on before had only 7k on it. After replaced the 02 i reseted the PCM and code came back. I checked for vacuum leaks and none were found. Idle is fine.

Could it be injectors or an injector? MAf? IAC vavle?> suggestions. The only code i'm getting is 176. PLus i also have an a'f ratio gauge. When i drive it's always running on lean most of the time when cruzing if that helps at all?


please help

edit: code added to subject.

If this has happened since your new wiring harness, they may have wired that O2 wrong.

Make sure the wires to that front sensor are not damaged.

Check at the connector for heater voltage.

Check output of the O2.

Although it could be a real mixture problem, it's doubtfull since the other O2 gives no code.

I dunno what you mean by an a/f ratio gauge... If it is really running lean, then the O2 sensor is doing the right thing and alerting the PCM. Could be an air leak somewhere on the intake for the front bank?

I dealt with the 176 on my car about a month ago. O2 sensor fixed it, but if the code had come back I would've been thinking air leak (that's what others here told me could give me a lean mixture on one bank).

Good luck.

Brent

Hey Lucas...

Try cleaning electrical components: MAF inside/out and others.


It worked for me and on my moms car.


later

BBorges. I have cleaned the maf inside and out in the past. I will do it agian but highly doubt that is the problem.




Roger you are right about the wire harness recall and having that doen to my car. i am going to have my mechanic check the wiring in the front . But i recently jsut did the a'f ratio gauge and they looked fine but what do i know?

How could they wire the o2 wrong while doing the wire harness? Isn't it jsut removing the old one and putting in a new one?

how would you check the voltage? and out put? voltmeter?

'
i have jsut talked to a friend who works at a dealer . He spoke to one of the shop guys and he said the same thing that you said. Some might be wrong withthe wiring or it might be damaged. Any suggestions where else i should look or do? i also agree about the mixture probel m but why wouldn't the other o2 throw a cel as well. AND i have check and so has my mechanic for vacuum leaks and there are none.

my gas miliage has also gone down a lot. Just wondering what are the effects of a o2 going bad? ex. loss in performance and gas milage ?

Yes, when your O2 sensor goes out your gas mileage will drop like a rock. I had my O2 repalced when the "check engine" light came on, cost $240 to get fixed, but if I didnt it would cost about $150 a year in gas because it wasnt working right.

If the signal from the O2 to the ECM is open or shorted to ground, that O2 will read lean. If it reads lean, more fuel is mistakenly pumped in . Same is true of a bad O2, but since it's new I doubt it's bad.


What A/F ratio gauge??? Where is it hooked in???

Cheap A/F guages use a normal O2 sensor for data. These can be very inaccurate if the mixture is out of range. Wideband O2's (also called a UEGO, or Universal Exhaust Gas Oxygen sensor) stay accurate but are very expensive.


Any high impedance meter will do for an operational check. An osciliscope is needed only to find quirks in a working system.

The O2 should be getting 12vdc to the heater, usually on the two white wires.
The signal to the ECM would be black for + and grey for - .
This signal bounces around with an average of about 0.45 vdc. If the output is zero, there is probably a wiring fault.

White plugs = severe lean condition. First step is to get a full set of Motorcraft double plats in there. Plugs should be light to medium brown in color with very few deposits.

One thing to mention, is your IMRC working properly???