RUNNING RICH?????

[ahm]

:repair:My 99' jeep is running very rich(black smoke and smell of fuel from exhaust). I got trouble code P0171 and P0505. I'm not sure what to do next?assgas:

i changed my TPS, MAP, new O2 before problem started w/ 2.5" exhaust and cat.
H E L P

 

[YMMV]

P0171 Fuel Trim System Lean Bank 1

1/1 Fuel System Lean-A lean air/fuel mixture has been indicated by an abnormally rich correction factor.


P0505 Idle Control System Malfunction

(M)Idle Air Control Motor Circuits-SBEC II

I would check the IAC, Plugs, Wires, and Coil. Remove the coil and check for any possible cracks as well to start.

 

[ahm]

thanks
i will check the coil. i replaced plugs 2x and the wires w/ no change.
how do you check IAC?, this is the 1st time for this code since the jeep started bustin my @$%%!.

 

[87manche]

does the 99 have COP?
If not then I would check the distributor.

 

[Blkxjkrawler]

Even with a new o2 sensor you might want to make sure that it is reading correctly. If it is stuck lean outside of the engines set parameters the pcm will set your P0171 and then will add fuel to try and compensate for the lean condition. So if you are not running lean on the first place, you get a ton of fuel dumped into the system and actually run rich

 

[ahm]

does the 99 have COP?
If not then I would check the distributor.

what is a COP and where is it located?
i have only one coil to distibuter

 

[ahm]

should i test the O2 or replace? how do you test the O2 sensor?:confused1

 

[CantonXJ]

what is a COP and where is it located?
i have only one coil to distibuter

"COP" is "Coil on Plugs" and I doubt you have it as I believe it was introduced for the 2000 model year.

Dave

 

[CantonXJ]

how do you test the O2 sensor?:confused1

The only method I've found for testing the upstream O2 sensor is the following:

"Located in the exhaust manifold. To test, using an ohmmeter, disconnect the O2 sensor connector. Connect the ohmmeter test leads to connector terminals A and B of the sensor connector. Resistance should be between 5 and 7 ohms. Replace the sensor if the ohmmeter displays an infinite reading. I don't know about you, but this test is pretty vague. They say it should be between 5 and 7 ohms, but infinite is bad. What if you get a reading of 13 ohms or 100 for that matter? I wasn't too fond of this test as I found it is a test of the O2 sensor heating element!. One other thing you can do with the O2 sensor is hook up the voltmeter to terminals B and C (I can't remember if those are the right letters, but you want to get the sensor wire (believe it was blue) and the ground wire, or just ground to something else) with the connector hooked up and the engine on, warm, and idling. You should notice the voltage jumping up and down in about 2 second or less intervals. If it doesn't jump up and down considerably or takes longer than 2 seconds to do so, change it."

Dave

 

[91xjtim]

Does it run rich right after start up before it warms up or after? If it is rich before it warms up all the way, then I would also check coolant temp sensor. Make sure its got 5V to it, and that the resistance tracks like it should as the engine coolant warms up/cools down as applicable.

 

[ahm]

The only method I've found for testing the upstream O2 sensor is the following:

I tested The O2 sensors and the 2 white wires are the only ones that had any reading, it was 1000+ ohms...the new ones are 33 and 12 ohms. the black and gray wire have NO readings. didnt test it running yet. :gonnablow

THANKS
PS. is this the only way to check them?

 

[ahm]

Does it run rich right after start up before it warms up or after? If it is rich before it warms up all the way, then I would also check coolant temp sensor. Make sure its got 5V to it, and that the resistance tracks like it should as the engine coolant warms up/cools down as applicable.

It runs rich ALL the time. And the coolant temp. sensor runs fm.5.7 volts and drops down as it get warm. I think its working right? :huh: THANKS

 

[91xjtim]

You should have a referance voltage TO the sensor of 5 volts(Read across the pins of the harness). The sensor will be read in ohms(Read across the pins of the sensor). I dont, however, have the range, youll need to look in the book, FSM haynes chiltons, should all have that info. It will tell you that it will read "X" ohms when cold and then "X" ohms when hot, and you should be able to watch it go from cold to warm as it warms up.

100.7Kohms = -40F
185ohms = 212F
1600ohms = 100F
450ohms = 160F

 

[ahm]

thanks for the help,
i'll look it up today after work(hate saturday). changed my O2 sensors, new one after cat and the one i replaced before cat. the truck works perfect, drove 50miles to work today.
thanks