irishbred5

Hello all. I’ve been floating around here for months trying to solve my issues on my own but to no avail.

Firstly, I have an ‘01 IS300 Auto with 164k. Had to put a motor in it that was from JDM New York and supposedly only had 66k on it. I have done a header and midpipe as well as an intake.

I’ll list out the issues and then give a bit lot information about them

Intermittent P1122
Permanent lean codes
Low Idle and misfire
2 MAF sensors lol

Okay so all of these problems started after the motor swap. The harnesses were different coloring wiring but all the same connectors. My tech that was helping me wired in all of the connectors that were brittle and broken. At first I thought maybe he got a couple crossed but that doesn’t seem to be the case.

Intermittent P1121

This used to be a lot worse than it is now. Before I couldn’t even drive a mile sometimes without it going into limp mode. Cycle the key and all is well, until it’s not. I have replaced both the TPS and APP with new sensors and set the TPS to 14.8% with the key on. I have also swapped the TCM for a used unit and cleaned the hell out of the TB. This issue only happens every once in a while now right after start up, no more randomly while driving. I’m thinking maybe wiring or voltage problems?

Permanent Lean Codes

B1S1 and B2S2 rarely read voltage. I’m sure it’s a wiring issue. (Only listing in case these all may be a related issue)

Low Idle and Misfire

This is a new one, maybe only about two weeks. Once warmed up, the car will idle at about 620 rpm and feel like it’s looking pretty hard. Weird thing is, that the plugs are fouled and I don’t see any spark jumping. Oh yeah, and if I turn the AC on, she purrs like a kitten and idles about 750.

2 MAF Sensors

For some unknown reason about 6 months ago, the car would just start and die. Traced it back to the MAF sensor. IAT was reading 40 degrees all the time. Replaced with a new sensor, same thing. Installed a new pigtail, same thing. For giggles, I spliced in an old GM IAT lying around and presto she ran. So I modified the intake piping and have to MAF in line, one as MAF one as IAT. Even with a new sensor, it Refuses to work if I wire it to only one.

So, those are my ghosts I’ve been chasing. Not expecting a quick fix all, just picking y’all’s brains for ideas of where to start or if there is a common thread here.

Thanks in advance.

2001SolarY

So what number codes are you getting exactly now? Also was it a US engine and from the same model and year?

irishbred5

As far as I know it’s from the same year and model. I gave them that info and took it on good faith they gave me a match. I however and not convinced that the harness that is in the car is from the same year and model. The reason I say that is some of the wiring colors do not match what ProDemand schematics show. I would say it’s 80/20 in favor of them being right. That may be age and discoloration too. The car had a couple bad oil leaks when I got it and everything was soaked.

Unfortunately I was tinkering with it yesterday and cleared the codes. They will be back in a couple of days and I’ll post them up.

2001SolarY

If it was from the same year range and model. It would have matched. It is also hard to say the issue without seeing current codes. Also It may even be wiring issues. Sorry. Not going to be much help. In a remote kind of situation. I would go over the wiring physically. Make sure it really goes from what your harness is. To what it needs to go to. Good luck.