WyattX_X

Okay so my 04 z has been down for some months now it was at a shop getting a new motor put in bc I was told my other motor skipped time. They found a 2005 motor and put it in and it ran like ****. He told me it needed a new maf sensor and new down pipes bc cats were junk, did that still runs like **** it misses real bad idles high and shakes the **** out of you at idle and worse if it’s in drive. I brought it to a new shop they said I had spark and compression was good but the injectors maybe weren't firing right so I changed them and still nothing. I hooked a scanner to it yesterday and got P1136, P0300, P0340, P0223, P0123, P1168. I changed the intake valve solenoids changed the cam sensor and still ran like ****, idk if it has a computer problem bc it’s a different motor or maybe the plugs arnt gapped right idk I jus know it misses real bad and shakes real bad and throttle is kinda unresponsive and when I gave the car to the guy who did the swap none of that was my problem. If anyone can help I would greatly appreciate it.

icer5160

iTrader: (4)

Could be a number of issues. I assume they put in a used engine from a 2005 automatic. That should be a direct drop in replacement. No, this shouldn't be a computer problem. A clean/direct swap might entail clearing stored memory and doing a throttle position relearn which also entails an idle air volume relearn. But otherwise, the engine should fire up without issue. What evidence did they have/use to support a MAF problem & replacement CATs?

You need a shop that can do proper diagnosis with a scope, otherwise you're just firing the parts canon. There's a number of things that come to my mind after seeing the plethora of codes present.
1) Damaged wiring harness, could have occurred during the swap.
2) Ignition Coil harness plugs could be mixed up.
3) (P1168) Upstream O2 sensor(s) could be damaged or not plugged in properly.
4) (P1136 & P0340) Intake solenoids and cam sensors, were these OEM or aftermarket? Only use OEM for these components. You should also always replace as a set on these engines.
5) New MAF sensor, again OEM or aftermarket?
6) Bad plugs, coils, or injectors. Again, were injectors OEM or aftermarket?
7) (P0223 & P0123) Throttle position sensor (TPS) & Idle air volume relearn, does it have the OEM throttle body or is it aftermarket?

I would take the vehicle back to the shop who did the swap. If they sourced the engine, they should have some kind of guarantee for their work. Clearly something isn't right and they should sort this out for you. I'm honestly shocked they would hand over a vehicle to a customer in this state, with this many codes present. If you don't trust that shop to sort it out, I don't blame you, But you're going to need an experienced pro to diagnose this, many things have been done/changed that will require additional time to check & verify.

Probably the easiest thing to check immediately are the coil pack harness plugs. These are commonly mixed up by those unfamiliar with these engines. I think cylinders 1 & 3, 2 & 4, or 4 & 6 are crossed by accident, this will lead to rough running conditions and major misfires. The harness plugs are labeled from the factory, but overtime these white labels disintegrate and flake off. You may need to verify based on wiring color and looking at wiring diagrams. Next, if you didn't use OEM sensors, I would immediately replace everything with OEM parts (MAF, CAM sensors, Injectors, & intake solenoid).

Another note, I have heard that Nissan ECM/PCMs will shutdown injectors and coils if certain DTCs are stored. For example, if the engine's computer is not getting good timing data from the CAM and Crank sensor correlation, then it won't know when to fire injectors and spark and therefore will not run until good timing data is present.

With the combination of an engine swap and parts canon being fired, you could have multiple faults. Anything from stored data needing to be cleared and relearned in the ECM to damaged or incorrectly connected wiring harness and faulty aftermarket sensors. Again, I would demand the shop who handled the swap address these issues. If they do not, then you will need to seek a professional who can do proper electrical diagnostics with live data and a scope.
Good Luck!
-Icer