697312lg

I got a 96 p72 head, using a pr3 intake, stock ek wiring harness, which ecu should I use??? Should I pick up a p72 ecu? p75? p28? p30? Lol, it would make sense to pick up a p72? I live in Nevada so I need to be able to pass emissions, help appreciated.

nealnanoHX

For emissions you need to stay OBD2 so a P72 is what you need for that, you will also need to run a knock sensor for this ECU. For the best performance, reliability and driveability you will want to have it tuned. A P28 ECU is besto for this. I have a S100 tuned P28 that runs my Ls Vtec but for emissions I have an OBD2 P75.

697312lg

So a p72/p75 would work best for emissions? But a p28 is best for performance?

grumblemarc

iTrader: (4)

Read it again. He said a tuned P28.

n*werk

You should familiarize yourself with ecu. P72 is a gsr ecu and p75 is ls ecu.

nealnanoHX

Yep. The P72 will be the best but needs more wiring as I said the knock sensor and if running the GSR intake mani then the sensor for the butterflies needs wired up as well. The P75 needs no extra wiring as long as the swap was done right and you have both O2 sensors hooked, the CFS hooked up and the IACV repined (I think that was all). Only thing with the P75 is no Vtec but that is Ok since you will be putting your TUNED P28 back in after emissions, and it will be a little lean since it is a B20 but that is fine also, it wont be too lean to cause any issues. Many people run the P75 ECU all the time on B20B swaps with no issues.

n*werk

Your using a gsr head with a b16 pr3 intake manifold?

697312lg

So from the looks of it a p75 thats obd2 can not be converted to vtec, and I need an 0bd2 to pass smog, so this one would only be used to pass gay smog emissions, Or i could use a p72(with a little wiring done) and call it a day, kay. Thanks that pretty much answered my main questions, now could u please tell me, P72 vs p28, why is the p28 better for tuning? Just wonderin, I got to make sure before I go out buying ecu's lol. If a p28 from an si is obd2 I believe, why cant I just settle with a p28, Im not callin you out, I know theres a reason, I just want to inform myself. Thanks.

697312lg

My bad I just did a little research, Just seen p28 is obd1, I was thinkin 99-01 si.

697312lg

A p28 looks for less sensors. I see.

697312lg

And about runnin lean, Ive heard a lot of stories of people runnin lean, bogging at low rpms, rpms dropping, car stalling at low rpms etc. Why is this, how do I know this isnt going to happen. OR, will this not happen if I get a good tune??? I wana do this right and I am going to take my time, So any input? Por favor, gracias lol.

nealnanoHX

P28 is best for tuning because it is OBD1 and already has the Vtec electronics. If you get a good tune you will have no issues.

697312lg

Arite I gotcha, So with a p28 and a good tune I shouldnt have any issues runnin too lean on fuel, ALSO, what injectors do you recommend using sir??

nealnanoHX

Stock B series injectors.

697312lg

the stock gsr injectors are fine?