Yeah, there's something very wrong with those numbers. They show very poor compression in all cylinders. Makes me wonder if maybe the rubber O-ring was missing from the tester. If those numbers are indeed accurate, you are right to look for another engine.

I would have guessed that the timing chain was off a bit, causing the valves to hang open, but you don't have any codes to support that. And the one dead cylinder is a bad thing. You could perform a cylinder leakdown test to determine what is causing the zero compression. https://www.chevyhhr.net/forums/how-...-engine-56053/

Put a 1/2 once of oil in #2 cylinder and try the compression test again, it might be piston rings. As for the MAF being off, disconnect the battery at the battery negative connect for 30 minutes to reset the computer parameters.

The 70 PSI readings might be just "operator error". Should be around 140

There is a chance they got the chain on wrong.

Might try the drop of oil trick and leakdown.

New head, zero compression = hole in piston.

Good news is when you replace the engine you already have a new head and hopefully timing chain

He might have reused the old head bolts, resulting in improper clamping force on the head and head gasket.

I'll try the compression test again later today, as well as the leak down test. I'll keep you posted.

You can get a bore scope that hooks up to a smart phone for less than $15 on eBay.

Update on the HHR. The motor went and now need to swap it out. I called a place a few hours away and They just got one the same day I called, an 07 hhr 2.2L. They asked if my car is drilled and trapped for air check valve or something like that. What and how do I know what to look for? Does auto and manual engine matter??

There's not much about the air check valve here. Only a few mentions that if it were there, it is drilled and tapped into the exhaust manifold. Call them back and ask if you were to use your existing exhaust manifold, would the question about the air check valve be irrelevant.

Air check valve ? Read post #2 it mostly for Saturn cars, so a plug will be required

2.2l Ecotec Compatability List - SaturnFans.com Forums

If it is an HHR it did not have the aux air injection pump. The answer is "not drilled".