Hello All,

I just replaced my engine in my 04 disco and all is well except I'm getting a P0130 code which points to the 02 Sensor on the Bank one infront of the Cat. I have an Innova 3130 code reader and all appears functional with the sensor. I have replaced the wires with a set of 8MM Kingsborn wires but did not replace the plugs since all was good prior to the engine removal with no codes.

Logically plugs would probably be a wise first step but they looked good and worked fine prior to this engine replacement.

 

Plugs won't help a dead 02, if you have near or over 100,000 miles, you should replace all 4 02's, also make sure the 02 connectors are free of oil.

 

Is that the only code you are getting?

P0130 - Front sensor LH bank stoichiometric ratio outside operating band.

That is indicative of an air leak somewhere. I would start by checking the sensor to see if it is loose. Then check your engine vacuum if it is tight.

 

One small thing I didn't mention that maybe the smoking gun. When I was installing the Plenum, one of the long bolts that hold the plenum to the intake would not hold in the intake threads. I'm now seeing this could be a vacuum leak throwing off the mixture.

Any suggestions on fixing the treads? I was thinking I could maybe get a little longer bolt or over size the bolt.

 

then you just may have answered your own question. try a tap and die first and see if it holds. If not, you may have to go oversized

 

Was able to replace the stripped Plenum bolt with one about an 1/8 inch longer and it holds. Took it for a spin and all was well last night. My wife just drove the car to work and she got the light which I could only assume is the same 02 code.

How can you test the functionality of the O2 sensor or what should it be reading at start, idle, etc? My Innova 3130 appears to have done the test but I'm not confident on what I'm seeing.

 

Few things to point out.
1. How long was your test drive? it should be more than 10 miles with multiple key cycles and 2-3 minute cooling down periods.

2. Is that the only codes your are getting.?

3. 02 sensor readings should change between idle and throttle . Unsure of the actual numbers but your scan tool should give you some voltages. Compare the left and right banks and report back with the actual numbers.

4. Also need you to check your exhaust for leaks. Manifold to block , collectors, etc. Check then double check. Also verify your O2 sensor is tighten down.

 

Problem Fixed---Used PB Blaster as penetrant on old sensor. Did not need a 02 socket only a 7/8 open engine wrench.

Found that the Left Front O2 Sensor was not changing value as the Right sensor was. Purchased a New Bosch sensor from Napa for $82 and all is fixed.

It sure is nice to have a scan tool that you can see Live Data.