Vac leak should be fairly easy to figure out, just add some light smoke around it to see if its being pulled in somewhere other than the filter. Could also be gaskets instead of vac lines leaking.

That evap code could very well be related.

Is it an aftermarket EGR? Did it come with a pigtail because the factory plug won't plug in? Did you already cut the OEM plug off? I'm just thinking it would be easier to put in a correct EGR that just plugs in to ensure there's not some kind of weird compatability issue here.

Constant on one cylinder, jumping around one bank, or jumping around all over the place?

What ECT values are you seeing at operating temp? We just need to make sure the pcm is getting reasonably accurate data here and that the sensor isn't giving crazy values.

So does it have any O2 sensor plugged in at all? Or are you talking about the rear one here?

IMO I'd forget about the TPS for now as you've already got a huge pile of issues to deal with.

Id get the cut wires ID'd first, then get the EGR functional (unless you truly don't have any functioning O2 sensors, then that would be #2), then check for a vac leak (per the whistling comment), then fix the ECT sensor issue, then tackle the rear O2.

If you get through all of that and it still doesn't run right, we can circle back to the scan data to look for other issues.

Just to double check is this the front or rear O2? If its the front one, that's got to be your #1 priority.

If youre talking the rear, then when you get down to that point in the fix it list, I'd probably get a multimeter on the plug to check function on the car side.

What caused the wires to get cut? Like someone just snipped the harness in half so you were just matching wires back up?

I'd be really worried about the purple and blue not hooked to anything. What harness are they in? It could be non essential stuff, but since we don't know where they go at all, I'd make this a high priority to figure out im case they're something critical. Do you have a service manual with wiring diagrams for the component closest to where the cut was?

 

Wires like that when i got it not sure. Front o2.

at idle and with thrittle never changes.

 

 

Have been trying to find vaccum and wire routing diagrams. Cant find anything but what looks like someone drew in art class. Love a vaccum routing so i could just replace all of it. Heater actuator didnt work when i got it but i found that line now it works ( blend door) other than that im lost. The ones on the intake just have plugs on them and dont know where they go either. Like i said though if you could here this thing run you would never imagine the problems under the hood. Just when you try to go wot its really choked. And starts missing. So helpful so far thank all of you very much.

 

I forgot to say but no it has no 02 plugged in at all. Isnt even a place for one in exhaust in back but front is new and there just not plugged in. Same with evap purge. Its not plugged in either. Both make it worse almost undriveable.

 

There really is no vacuum lines on these, very few. Because the 3400 is used in a couple different vehicles, the intake usually has one vac connection used and another that is capped and that is in addition to the big line connecting to the brake booster. If you have the Cali emissions package, there are a couple others. I typically use starting fluid and mist it around the engine while it is running. The goal is to listen for the RPM for change. If it does, you can start finding your location of a leak that way.

Sounds like your replacement EGR is generic and used a non-factory connector, is that correct? Did it come with instructions that explained the pin outs for the white wires? If not, you are just taking guesses. Personally, I would have used an EGR that uses the factory connection.

I'll be honest, it sounds like you have multiple items going on. There is no magic "this is it", I think you entire problem is related to solving each of these mysteries. I am still concerned you mention you have no cat, yet does not sound like you know what was done to avoid a P0420 code as a result, especially since I assume that is where you said there is no spot for an O2 sensor.

And Bumpin' is right, as long as you swapped 3400 for 3400, this engine swap should not have required any re-wiring of connectors. At most, maybe swapping sensors over and worst case swapping the upper intake due to changes GM did over the years for the EGR on the 3100/3400 platform.

This bit about the front O2, that is required as part of the car's fueling system. Leaving it unplugged means the PCM is compensating without the required reading. So if you say it runs worse with that plugged in, it's because you have another problem that needs solved. But if you are getting identical readings for that O2 plugged in or not, something else is also wrong. I am guessing you are reading the rear/downstream O2 sensor and someone installed an O2 simulator since you said there is no spot for it.

And these relearns you mentioned for TPS and Trans, that must be something generic for your bluetooth device, as these cars have no such thing. The TPS is simple to install and unlike the TPS of years back, there is no calibration (you used to require reading it with a volt meter to get it at 0, these new ones lack such an adjustment).

And those cut wires you have a pic of, I am not sure where they go. I have a 3400 Grand Am, but it's wiring harnesses, colors and routing is going to be different than the Monte.

There are a lot of questions about this car to straighten out. I would start with these items:
- Research the potential vac leak
- Solve this EGR issue (even if it means getting a clip of a junk yard factory harness to fix what you have going on).
- Solve the two cut wires that you are showing.
- Ensure all harnesses and sensors are connected.

These should be easy items. After that, clear codes and see what ones return. Hopefully this makes some progress and then start attacking the next code.

 

Not much time to respond as I'm at work, but WOW, thats a really bad situation.

I'd definitely stop trying to go WOT (and personally I wouldnt drive it at all) without any O2 sensor and all of the other issues. Without an O2, it can't adjust fueling so its running on the base map alone. With the pile of other problems, the fueling it needs will be skewed from a good running stock engine (meaning the base map isn't sufficient), which means you've got no idea what AFR its actually running. Could be 10:1, could be 18:1 or it could bounce anywhere between depending on situation at the moment.

IMO that's flirting with cooking the engine.

I'd focus 100% of the effort on getting the front O2 hooked up and figuring out why it won't run with that plugged in (using your scan tool). That's a fundamental piece to operating an EFI system.

 

so i replaced the purge valve and plugged it and the oxygen sensor in and the fuel pump ( already had ordered and cheap and easy to do so just did it) The egr is aftermarket from autozone. It also came with a new pigtail witch someone had already replaced but i replaced as well, Now it runs like a champ. i mean i never went over 45 just around town here and gort into it a few times and something worked. Miss is gone, hesitation (bogging down) is gone as far as can tell from just driving it awhile. Now im sitting on the 2 wires and a check light that still says oxygen sensor heater. and no response and its turned on 1 not 2 but all else aside i have made great progress. you guys are great. reason why there is nowhere to put o2 in back is there is no hole in exhaust for it. whern i got it it was straight pipe all the way . So now the wires to 02 sensor maybe? by the way the only code im getting for it now isp0134The response doesnt change from sensor.. sorry about the earlier assumption about heating element.. Had 6 codes yesterday doen to this one now and the abs light What great help there is here. Also after i change pump and purge valve i reset everything i could, trans relearn, throttle relearn, fuel trim, Tps sensor. did the relearn process

 

I understand the exhaust was straight piped and who ever did it never put a bung in for the rear O2 sensor, but you still have a BIG question to answer. Is the car still running without a rear O2 sensor? If so, why are you not getting any rear O2 codes (like a circuit open or P0420 or any of the others)? The lack of the rear O2 codes when you don't have a rear O2 plugged in is not a random miracle. I only know two ways to do that. Method one is a plug in O2 simulator (which means the wiring for the rear O2 sensor is still there somewhere with a little item plugged into it). Method 2, someone has modified the programming in the PCM. If the programming in the PCM has been altered, what else has been changed in the programming? And if the programming has been changed, that could complicate things you are chasing down.