Quote:
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.