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Bought a used 04 RSX Type S Just realized it was a K20Z1 swap

3K views 4 replies 2 participants last post by  IronGumby 
#1 ·
Hi guys I am new to the RSX and the forum I bought a used 04 Type S the the P.O., a shop, had replaced the motor and had a CEL they couldn’t read due to a Communication error with the ECU. The car Had 100k on it so I took a shot and bought it. Every light was on but the car actually ran well other than A bouncing Idle. I took it to an Acura Dealer and had them reprogram an 04 PCM. It fixed the lights but not the idle of course. I ordered an IACV and a TB gasket for an 04 (because I assumed it was replaced with the same year) I put it back together and the car would start, idle and die under any load. The car had a STFT of -27.3 a LTFT of -7.0 and ran pig rich. It threw a p0172 code. Since It ran well before I messsed with the throttle body. I ordered a new OEM map sensor for an 04 and a idle purge solenoid. When I went to put the solenoid on I noticed it was backwards. I then realized I had an 05-06 TB. I investigated further and noticed That the motor is a K20Z1 and the tranny is a X2M5 6 speed from an 04. What do I need to make the swap as right as I can? Do I need a 05-06 ECU? Do I need KPRO? I am guessing the wiring was changed as everything appears to match up. The car ran pretty well before I messsed with the throttle body. Thanks in advance. Pat
 
#2 ·
What an awesome discovery! hah. I mean, it does make 10hp more stock er something like that over a K20A2. But anyways...

Yes, the TB's are different from 02-04 to 05-06, in how they port the MAP pressure to the MAP sensor on the TB. I don't know your direct answer, but I think your options are as follows:
1.) Use an 02-04 TB
2.) Relocate the MAP sensor to the intake manifold?
3.) Mess with the port hole on the TB gasket (aftermarket phenolic one recommended)... in your case, plug it??

I *think* this is your problem? Maybe review the following threads and determine if this is the problem. (For reference, this PRC intake mani swap discussed is an 02-04 intake manifold intended to be used on a 02-04 throttle body, so when a 05-06 TB is used, the port hole has to be dremeled into the TB gasket to allow a path for the vacuum to travel. In your case... I think you aren't supposed to have this path, so if you get a plastic 02-04 TB gasket with that port hole missing/blocked, then maybe that will get the right MAP pressure to the sensor??)
https://forums.clubrsx.com/showthread.php?t=909722
https://forums.clubrsx.com/showthread.php?t=1110905
https://forums.clubrsx.com/showthread.php?t=315086
https://forums.clubrsx.com/showthread.php?t=777277
 
#4 ·
Got it running with a w 2005-2006 throttle body gasket

Thanks Iron Gumby. I put a 05-06 throttle body gasket in, cleaned and put the old IACV back on and it started running like it did before but with a smooth idle. It still running rich. Long term fuel trims are -18.3. Do you know if the EVAP systems are compatible? its an 02-04 ECU and canister etc. I am thinking of putting K-pro in and getting it tuned. I have a Thursday appt with a tuner in Sunbury. Thanks again, Pat
 
#5 ·
Sounds like it was only related to your IACV needing cleaned then. But the rich air/fuel ratio Idk... Maybe you have an 05-06 primary oxygen sensor installed when really it should still be an 02-04? Idk about the proper fuel trims or the EVAP systems but hopefully someone can chime in
 
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