Another Saturn! 06 with a 2.2l engine. Don't remember the mileage but greater than 100k.
Car came in with a complaint of a P0101. Confirmed code and on the test drive car lacked power like the exhaust was plugged.
Fuel pressure tests OK @ roughly 60psi.
MAF VE around 70%.
Tune up parts in fair condition.
All fluids OK.
Engine vacuum with B1S1 O2S still in place is very low.
Engine vacuum with B1S1 O2S removed.
I didn't get a picture of the exhaust back pressure reading but it was normal @ 3000RPM.
A second road test with the B1S1 O2S confirmed exhaust back pressure readings and ruled out a plugged converter.
I happened to have a known good MAF sensor from a parts car so I bolted it up just to see...
At this point I recommend removing the valve covers and verifying engine timing.
But, it's been a while and I haven't heard back from the customer...
At this point it may just be idle speculation, but... Anyone ever have a similar car roll through? Anything I missed?
Given the lack of a P0068 or a P0106 it's hard to say what the problem is without verifying cam timing. Though at this point I'm fairly certain cam timing is off.
Another thing I wish I had done was to get a running compression test.
I really wanted to see what was wrong with this piece and it still kind of bugs me. But if you're not getting paid what can you do?