Thread: G20 ECU from my 95 SER into 98 SE

I know the 98+ throws a cel. I did my research and I know I would need to rewire, switch rear 02 sensor, and switch a couple vacuum hoses to get rid of the CEL.

However, I do not care if it does throw a cel. My question is, if I do plug and play my g20 ecu into my 98 without doing the necessary adjustments to clear the CEL will it have any adverse effects on performance? Ive gotten mixed answers after searching and reading old threads and hoping to get clarity on this.

Nope, you will get the higher rev limit, same as th B13 i believe, and removed 109mph speed governor. But it will throw the MIL as you alreeady pointed out. Everything else the same.

It will also give you a slightly better performance to your car. It did to mine when I swap the G20 on it feels a little more responsive. I believe is because the G20 is a 4 door and the fuel maps are a little optimize for the weight of the G20. Since our cars are 2 door and weight less that's why I believe in my opinion that the car felt more responsive and it picks up quicker in the RPM's

Yeah, my 200sx ser felt a lot better after I swapped in my g20 ecu. I was just concerned about if I put it into my 98 SE, it'll have negative impactunless I rewire because someone mentioned he was getting low voltage on his tps and rough idle after g20 ecu in his 98 but it was fixed by the rewire.

Glad you like the upgrade. Is a better and cheaper way to raise your rev limiter, take off the speed limiter, and a little fuel map optimization. Instead of sending your stock ECU to JWT to have them do that. The next thing I recommend for you towards a better ECU is a Calum Basic OBD2 ECU or a NIStune Type 4 Board ECU and you can tune your car on your own or have someone tune it. JKtuning still haven't come up with a OBD2 ECU for us with OBD2 ECU. The only thing you can do to get one of the JKtuning ECU is get a stepdown harness I believe they also sell them in their website or just contact them.

I had a 98 SE w/ the G20 ECU with all the bolt ons including JWT S4 cams, and I never noticed any problems with the idle besides the already lopiness especially in the mornings.

Only thing was the CEL.

i agree the g20 ecu does add a bump in power

Well I sold my MT G20 ECU along with my 95 SER because I had bought the car with an AT ECU and didnt want to sell it with a check engine.

So now im looking to buy another. I've found AT G20 ECUs for much much cheaper than MT. I know it'll work but my question is, are the AT G20 ECUs tuned the same way as the MT performance wise?

Yes, an Auto g20 ecu will bump up power for a.car that came with an auto. My buddy who rally races his 200sx proved this theory. He may have an auto g20 ecu for sale I could find out.

My 98 SE is 5spd. Based on what I've the AT G20 ECU should work although I read storm88000 had idle issues.