Loss of power under load...

[OFLx5]

UPDATE! SOLVED!!!

Removed both PRE CAT O2 sensors and took her for a spin... BIG BIG DIFFERENCE! Looks like my cats are plugged...

So again.. SOLVED. Thank you all for helping!

[StephenVA]

To confirm your cats are PLUGGED up. Tap into a good source of intake manifold vacuum and insert a Vacuum gauge.

• Read engine vac at idle
• Read at 1500 RPM (no load required)
• Read at 2500 RPM again no load required

If you vac number drop as RPM increases, your down stream exhaust is indeed blocked. Drop the cats and see if the number change, because a collapsed pipe and or muffler further down stream will give you similar results.

If you are really ambitious, there are pressure gauges and lines that can be screwed into the O2 ports upstream and downstream of the cats to see the drop live.

[lo_jack]

Originally Posted by StephenVA

To confirm your cats are PLUGGED up. Tap into a good source of intake manifold vacuum and insert a Vacuum gauge.

• Read engine vac at idle
• Read at 1500 RPM (no load required)
• Read at 2500 RPM again no load required

If you vac number drop as RPM increases, your down stream exhaust is indeed blocked. Drop the cats and see if the number change, because a collapsed pipe and or muffler further down stream will give you similar results.

If you are really ambitious, there are pressure gauges and lines that can be screwed into the O2 ports upstream and downstream of the cats to see the drop live.

Where is a good place to tap manifold vacuum with a normal pressure gauge? I think I have the same problem and just happen to have a boost/vac gauge lying around.

[upallnight]

Instead of a vacuum gauge, I would tap in a compression pressure gauge at the 02 sensor.

See this video at 3:56

https://www.youtube.com/watch?v=9TlygJMxTps

[upallnight]

Originally Posted by lo_jack

Where is a good place to tap manifold vacuum with a normal pressure gauge? I think I have the same problem and just happen to have a boost/vac gauge lying around.

If you have the app Torque I believe there is a PID that measure manifold vacuum.

[upallnight]

Originally Posted by OFLx5

UPDATE! SOLVED!!!

Removed both PRE CAT O2 sensors and took her for a spin... BIG BIG DIFFERENCE! Looks like my cats are plugged...

So again.. SOLVED. Thank you all for helping!

Looks like this guy nailed the problem.

https://xoutpost.com/1097105-post26.html

[lo_jack]

Originally Posted by upallnight

If you have the app Torque I believe there is a PID that measure manifold vacuum.

I do have pro version. Hadn't put it on X5 yet, only cheaply built MKV Jetta and in-need-of-tune-up Navigator. Video was on point. I'll be doing that next time X5 leaves the garage. Thanks.

[bcredliner]

Originally Posted by upallnight

Looks like this guy nailed the problem.

https://xoutpost.com/1097105-post26.html

I don't think Srmmmm cares if he is right, if he does, he should know helping someone is not a contest.

[upallnight]

Originally Posted by bcredliner

I don't think Srmmmm cares if he is right, if he does, he should know helping someone is not a contest.

It's not a contest, but people should be aware as to who have knowledge as to how to fix these cars.

[bcredliner]

Originally Posted by upallnight

It's not a contest, but people should be aware as to who have knowledge as to how to fix these cars.

Much of the time incorrect contributions here are not an indication of lack of knowledge. If that were the case none of use are knowledgable as to how to fix these cars.