Thread: Code help after engine replacement

I changed the engine in the 2004Grand prix GTP after the blown head gasket and cracked head problem but that awhole different story. But anyway, I studied the hell out of Bills post “How tochange an engine out Bill’s way” or whatever it was and I am telling anyonethat is planning on doing this need to know that step by step and it will be apretty easy job to do. But Bill I must be honest it took me close to 25 hoursto do rather than the 2.5 hours you say you can do it in. (you are a GOD!!).But here is where I am at now. There are a couple of problems I am havingtroubles with.
1. The car will run but the idle jumps up and downand it eventually dies. It revs up and down up and down up and down and thendies.
2. It is throwing 2 codes. “P0068 MAP/MAF “throttleposition correlation” and p0101 “Mass or volume air flow circuit range/ performance”When it does this the dic shows “reduced engine power”
Any ideas will begreatly appreciated. I just don’t know where to start.
Thanks, guys!

I'm with Fordie on checking the maf sensor first.

GOn the amount of time it tood you. That's reasonable and expected for someone doing it their first time. You had to look for the bolts/nuts, find the connectors etc. I wrote that up was to include the tool sizes etc, to save some time. By having the right tools next to you when you are at the car takes out a lot of time walking back and forth to the box. Glad it worked well for you overall. If you have to do another, I bet you cut that 25hours in half based on experience. Do it a few more times and you'll be doing it while you are on the phone via a bluetooth ear bud, diagnosing someone in Ohio and it'll be done in about 6 hours total. I can get an engine out in 2-2.5 on most cars. Reinstalling..well that takes probably 3-4 hours.

I remove via air tools mostly and reinstall mainly with hand tools. That way I don't snap anything with air or overtorque. I also know exactly which tools, where and what has worked well for me. Intrigue98 is a local and has helped out on tons of work in the garage. When Scottdoggs came up for a trans swap, Intrigue was running late. I started and Scott told me I was cruising pretty well. Intrigue walked in, I handed him a long prybar and w/o speaking he knew exactly what was being done and where he was needed. That blew Scott's mind, and was so awesome. Intrigue knows that the tool I handed him is only used for popping the balljoints. That's how much knowing the car/tools can do for you.

do you have your map sensors hooked up properly? One should be open to the air and the other gets vacuum. If you look at map on the pcm, you should see about 20 hg of vacuum at idle. If your baro gauge reads that..it'll goof things up.

I love diagnostic aids that support my first ideas. =0)
http://hsv-gts.ls2.com/0506GTODTC/DTC%20P0068.pdf

Keep in mind this is for a 98 Bonne, but it gives us a description of how/what might be possible.
http://www.justanswer.com/uploads/mc...P0101Debug.pdf

I'd think that either one or both are peeved. So the question is which sensor is unhappy? You could unplug maf and drive. So then maybe it's only the map/baro sensors. I'd start looking in that area.

That's the side it would typically be hooked to. Let me pose a question though. Which map sensor did you hook up to the connector for the pcm baro input. Being side by side with identical connectors...you might have them backwards. Do you see a reading on the baro that looks like LIM pressure/vacuum?

If it's not the connectors (maybe take a mirror and check for bent pins in the sensors), then maybe there is a bad fuse. I'd then check the voltages at the maf and map sensors since that is what you are getting codes for. I'd think it is something super simple because you did a simple motor swap. unless the harness got pinched or a wire chopped by mistake, there's little that can usually be the problem.