yamaha

My never ending delima with CEL's on my Elantra is finally getting to me. This started a few months ago after I blew the engine and torque converter on the stock BetaI. After getting the BetaII engine and BetaI transmission back into the car, I have had these four codes. The P0131 and P0135 refer to the O2 sensor low voltage and heater circuit malfunction. I bought a new primary oxygen sensor from Advance Auto Parts, repolaced the old sensor, and the P0131 and P0135 codes still persist.

I thought the oxygen sensor may of been bad, so took it back to get a replacement. They gave me a new Bosch sensor, the same as the old one, put it in, and the same issue occured. I've been doing some research and it seems the ECU is very picky about replacement sensor's. I called around to local dealer's but the cheapest sensor I could find was 120USD. I really don't want to spend that kind of money just to get rid of of a oxygen sensor CEL. Would a sparkplug fouler be a cheap solution to this issue? I read up on them and it seems to make the sensor not get a direct reading on the air/fuel mixture.

Now for my other two codes, the P1513 and P1553. These two codes refer to idle air control issue. Before the engine was swapped out, I had no issues, but since I have the BetaII engine in, these codes still persist. I changed out the IAC, TPS, MAF to see if this would correct the issue, but it has not. I did some more digging around and believe my issue may be in the connector. I'm going to attempt to get a extra connector from a junked car to see if it solves the issue, if not, I will be back to the drawing board.

Doe's anyone have any experience/input into these CEL's? I'm really getting tired of these reoccuring issues. HELP!