Pmulls870

I must have missed a vac line somewhere. I'll do some more searching and report back.

Pmulls870

So I think I found it, I changed the oil to 0W-40 this morning and ran the crap out of the car and got her nice and hot. I got it to misfire on #4,#5, and #6. The 0W-40 was thin enough that it was creeping past the valve cover gasket. It's too cold to fix the issue today but eventually I will fix that. I believe that would be the issue.

Pmulls870

Can anyone confirm this as a likely cause of a misfire?

Prospeeder

No that wont cause what your experiencing. 4 5 6 are on the same side of the engine. You want to consider things that effect only that half. The brake booster and all the plumbing for the breather system come from a vacuum source biased towards to 456 bank of cylinders. Also think maybe melted down or broken apart catalytic converter only on that side. Even camshaft timing on that bank, either belt or chain. But it should set a fault code if that were the case.

Pmulls870

How do you test a catalytic converter

Prospeeder

Well take it to an exhaust shop they will drill a small hole and insert a gauge to read backpressure in the exhaust

Pmulls870

Can you remove the catalytic converters and use a resistor in place of the post Cat O2 sensors?