ANY IDEAS WHAT IT COULD BE?

  • Tiny
  • shanegorum
  • 2003 Isuzu Axiom
  • 72,000 miles

Runs very rough even back fires when givin alot of gas flooring it it will take off and run ok and it idels ok but when given just a little gas or normal driving it dont want to go has codes for random misfire and both pre cad. O2 sensors but if codes are reset it will run a lot better for some time then goes back to running the same way

Sunday, October 14th, 2012 AT 5:29 PM

8 Answers

  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

What codes are you getting?
Have you checked the spark plugs and related components?
Check fuel pressure as well.

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 5:37 PM
  • Tiny
  • shanegorum
  • Member

New plugs and it has coil packs the codes are both pre Cadillac converter o2 sensors and a random misfire 1 of the o2 sensors are new and when we reset the codes it runs ok for a few hours

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 6:02 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

I need the codes, not the decription.

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 6:22 PM
  • Tiny
  • shanegorum
  • Member

I don't have the codes did them at auto zone ill try to get them if I can

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 6:24 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

Will wait for them.

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 6:28 PM
  • Tiny
  • shanegorum
  • Member

Ok 1 code is p0151 then it just says random misfire

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 10:55 PM
  • Tiny
  • shanegorum
  • Member

And po131 pd

Was this
answer
helpful?
Yes
No
Sunday, October 14th, 2012 AT 11:27 PM
  • Tiny
  • KHLow2008
  • Expert
  • 41,976 posts

Here are the diagnostic aids.

Diagnostic Aids

Check for the following conditions: Check HO2S pigtail wire for breaks, contamination or grounding on exhaust manifold. Check for intermittent ground in signal wire between sensor connector and sensor.

Check PCM grounds.

Check fuel pressure.

Perform injector balance test.

Vacuum leaks: check for disconnected or damaged vacuum hoses and for
vacuum leaks at the intake manifold, throttle body, EGR system, and PCV system.

Exhaust leaks: an exhaust leak may cause outside air to be pulled into the exhaust gas stream past the HO2S, causing the system to appear lean. Check for exhaust leaks that may cause a false lean condition to be indicated.

MAF sensor: the system can go rich if MAF sensor signal indicates an incorrect engine airflow measurement that is not correct. Disconnect the MAF sensor to see if the lean condition is corrected. If so, replace the MAF sensor.

Fuel contamination: water, even in small amounts, can be delivered to the fuel injectors. The water can cause a lean exhaust to be indicated. Excessive alcohol in the fuel can also cause this condition. Check for fuel contamination.

If none of the above conditions are present, replace the suspect H02S.

Was this
answer
helpful?
Yes
No
Monday, October 15th, 2012 AT 7:30 AM

Please login or register to post a reply.

Similar Questions