We just finished putting a head gasket in the car.

At first it wouldn't start but after some fiddling it started right up. The the idle was terrible. It sounded like it was idling at 400 rpm and revving up to 1000 every 2 seconds. We found a big vacuum line unhooked, all good. It fixed that issue.

Now it starts up quick, but idles rough. Not bad, just a little shaky. The bigger issue is that it wont rev above 3000ish rpm. There's no tac gauge so I can't tell exactly what RPM.

It sounds like a rev limiter. It's not stalling, it just will not go past that rpm.

We *tried* resetting the ECU by starting, stopping, unconnecting battery, idling etc. A tutorial I found in here from 2005. I do not know if it worked.

We're getting o2 sensor 1 and 2 codes, and cylinder 1 misfire.

The o2 sensors are messed up. We have the downstream o2 sensor(Bottom of the exhaust manifold in the cat) hooked up to where the upstream should be connected and the upstream not connected to anything. The plug where the upstream should hook to has the same connector as the sensor so they don't connect. The downstream o2 sensor does plug in there though. We can't find the correct plug for the downstream. Is it under the car?

Thank you.

 

compression test to see if the head is sealing, if you didn't atleast resurface the head back to a straight state instead of a warped state it's not going to seal

 

Compression is 150 across the board. Seems low. The head was supposedly resurfaced. Better than 120 120 120 20.

But as for the original problem, it's solved. The idle is still slightly rough but it now drives great with no cutting out. It starts to shake at 60 mph but I'm sure it's either tires or front end something. Nothing too bad I don't think.

Still don't have the plug for the o2 sensor.