Hello, this is my first time making a post so hang in there for me. I have a 5spd manual 99 Honda Civic EX Coupe. It has a b20b Engine with a “Gsr” transmission with a P75 ecu chipped(idk the chip brand) the reason why the transmission part has air quotes is because the vin plate on the trans has been removed so not sure if it’s a real gsr. I can count the teeth or do the 4th gear test but haven’t gotten to it because the car goes into a “limp mode” as some would say. It only revs up to 3.2k and bounces and on hwy speeds I can get it up to ab 65-70ish if I’m lucky. It goes into limp mode randomly, when it is not in limp mode it cold starts on well, idles well, and pulls/ drives well. Any ideas on what it could be? Bad chip/ecu ?

 

When it goes into limp mode, the check engine light should come on. Then you should have some codes stored that should tell you what the ecu thinks is wrong. If that isn't happening, then who knows what's wrong (ECU failure maybe. Maybe consider getting a stock B20B ECU from the matching CRV instead of chipped mystery ECU. P75 is an integra B18 non vtec I think.

 

I see, I forgot to mention that the obd2 port on there doesn’t work(not surprised), not sure if its cause it’s the harness that maybe got wired in wrong, or should it be a obd1. As far as the ecu goes I could try doing like a trade for a stock ecu p75 or even look for a crv ecu the thing is I’m not exactly what year crv it came from. This is my first Honda so I’m learning everything as I go.

 

Sounds like need to reverse engineer someone else's wonky work.

If it's OBD1 figure out how to jump the pins at the ecu harness plug so the check engine light will blink out codes.

​​​​​​​B20B in the US came from a 96-98 CRV. If you can find a manual transmission ECU, its a good start. Unfortunately you may need to go over engine/chassis harness very closely as though you were doing a brand new swap.

 

Send the Ecu to a repudiable tuner or shop and have a real EMS installed like Hondata S300 and have them load a B20 base map and you should be good with no more issues. If you do they will adjust the tune or base map easily.

Send the ECU to them.
Phearable.net: Honda & Acura Performance Solutions

 

Hey guys just wanted to update you guys, Turns out I had a chipped ECU from a junkyard, I was able to get a stock ECU from a friend and now the car runs well, I’ll get a tune for it in the nearby future. I will be replacing the wire harness soon cause I got to replace the clutch so I’ll be doing it all at once with a good cleaning of the engine and the bay. thanks for all the helpful tips

 

I’m not sure if it’s an actual common occurrence with older ecu’s but with my 1995 Honda Civic Hatchback, when it gets cold my car when trying to turn it on, the fuel pump doesn’t prime. I saw a YouTube video on a how to fix it, 1. Heating up the ecu or a certain section of it that controls the fuel pump causing it prime and shortly after it’ll continue to work as normal or 2. Change the ecu. I’d prefer to change the ecu because heating up the ecu everyday would suck. So the problem at hand would be finding a proper ecu to change the oem one with. I also plan on k-swapping the civic, so if one of you guys happen to know what ecu I can buy so I wont have that issue and what steps would be needed to properly swap the ecu but also at the same time a ecu that would work good with the plans of the k-swap