Rep Power: 0

Help me out here guys.
I recently installed a 2005 Honda Civic lx transmission and engine into a 2002 Civic vtec. Everything came out good. Couldn't transfer the intake manifold with catalytic from 05 to 02 cause the mouth wouldn't fit.
Now 05 has both sensors at the top, one for air/fuel mixture and one for catalytic converter. Since i used the manifold from 02 which was a vtec i just connected one sensor,so one is vacant.
Everything work's good EXCEPT the issue is that the car doesn't go past 4000 RPM. I have found two faults and tried resetting, came back again. Checked both sensors and they are good. I have attached pictures the same.
Please advise.
Thanks

 
Rep Power: 517

First problem I see is you should have swapped the original wiring harness over to the new engine. 0_o

Second problem is you should have VTEC fault codes because the LX head has no VTEC and the EX PCM is looking for VTEC signals to be correct. THAT fault should cause a code and abnormally low rev limiter.(when you drive it)


Also
The 2002 PCM cannot read an AF sensor, it was made to use a regular oxygen sensor.

Use both oxygen sensors for the 2002 car along with the cat and exh that for the 2002 car.

Maybe an extension harness will let you reach the rear sensor....but I cannot tell you if the rest of the wiring into the PCM is the same.
EDIT: I don' think there is any easy way to make the wrong engine harness (newer lx) work right with the older EX PCM.


Sitting still it won't go over 4k??? Might be normal.

Or were you driving it around and discovered this? Not normal.


How did the last engine fail? Could it have damaged the cat causing an exhaust restriction?

 
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Thank you for the prompt reply.
It doesn't go above 4k while driving.
I'll work on it again this weekend and keep you updated or incase if i have any questions,
thanks again.

 
Rep Power: 0

One very likely cause for this is that the 2005 EX ECU is still looking for the VTEC Oil Pressure Sensor that the original engine had. Once it doesn't see that sensor or gets a faulty reading from it, it automatically limits your revs to 4000 rpm for reasons of self preservation for the engine.

As ezone said, perhaps you should install the original harness, and go a step further to swap in the 2002 ecu as well, that would eliminate the 4K rpm rev limit. Of course, you'd have to get your key programmed to this new ecu as well.

 
Rep Power: 517

Yea a 2002(ish) LX ECU because it won't ever look for the missing VTEC system