hey guys ive got a 90 4runner 3.0 and just noticed a significant drop in mpg, loss of power, and now my idle has gone from 800 to 300 and dies at idle if i turn on ac. the only thing i have done is chopped off stock muffler. also im throwing a code 52. any input is appreciated!

 

does it ping?
https://www.yotatech.com/forums/f116...thread-216933/

 

code 52 is knock sensor circuit.... more than likely the pigtail wire harness coming off the sensor (which is located under the intake plenum btw) has given up on life... pretty common for these rigs. It is a bit of a job to get to it, so I would advise replacing the pigtail (about $12 from dealer) as well as the knock sensor itself (prolly about $150-200 from dealer).

Good luck!

 

I just recently rebuilt my engine and started it up for the first time, I got that same code, so I took it apart, starting with the front cover, coolant passage, intake tubing, upper intake, fuel rails, and then the lower intake. I replaced the wire and ever since, I've never had a problem, I highly recommend it, the wire itself isn't to crazy expensive, and the sensor it self usually doesn't go bad. I do not recommend doing the knock sensor relocation, just get a wire and install it or have it installed. I had my fuel injectors rebuilt too while I was under the upper intake.