MIL after VTEC Swap
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MIL after VTEC Swap
Hello all, I have a 2005 Civic LX and have a technical question. Forgive the lengthy post, but I wanted to provide as much info as possible. So, after 240k miles, I replaced the motor with a jspec Motor. The one I was sent was a vtec motor. After some research On how to get the vtec to function, I purchased a junkyard PCM from a 2002 EX model. I had the immobilized programmed so the car starts. I added the two wires to connector B to my existing PCM harness to activate the vtec solenoid and to the oil pressure sensor for the vtec. The vtec works great. I do have a check engine light for DTC P0135. Checking the wiring diagram for the LX and EX models, it appears I also need to add two wires to another connector for the HO2S element. Is this correct? Do I need to get a different sensor (for an EX model I assume)? Any help is appreciated. Thanks!
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Re: MIL after VTEC Swap
normally the jdm motors don't have the vtec pressure switch, you have to swap it over from the old to the new, but since you don't have one you have to purchase one separately or source one separately from a junkyard
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Re: MIL after VTEC Swap
My motor came with the Vtech solenoid on the back of the head, but it did not come with the oil pressure solenoid. I picked up on of those with the EX PCM from Pick A Part and wired it in. The vtec works great. My concern was about the MIL for P0135. I believe I might need to rewire the O2 sensor to different pins to get it to function properly. Do you know if this is correct?
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Re: MIL after VTEC Swap
The lx and ex models have the oxygen sensors in different spots. On the ex they are combined with the cat in the downpipe while the lx has them in the exhaust manifold with the cat.
Are you sure you are still running both oxygen sensors to begin with ?
Are you sure you are still running both oxygen sensors to begin with ?
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Re: MIL after VTEC Swap
Both oxygen sensors are still physically in the manifold and connected to their harnesses. As for if they’re both functioning, that I’m not sure. The MIL came on instantly for P0135, but now that the car has some miles on it, it’s entirely possible there are more codes for O2 related problems. I’ll scan it again tonight.
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Re: MIL after VTEC Swap
I used The LX exhaust on the new motor. I had it and it was cheaper and easier than swapping to the EX exhaust. I can check the salvage yard for everything but the cat. I’ll check into it this evening and start by seeing if I have new DTCs.
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Re: MIL after VTEC Swap
Ok, I only have the one DTC, P0135 B1S1 O2 Heater. Backprobing the wires on the upstream O2 sensor, I am not getting power or ground to the heater element. I think the problem is I have a 2005 LX with a 2003 EX PCM. The 01-03 EX was wired differently on the heater element than an 04 EX/04-05 LX. Does anyone have a wiring diagram for the upstream O2 sensor for both the 03 EX and 05 LX? Thanks.
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