*S14 KA24DE CEL and weird idle problem HELP!!

[csw1986]

Hi guys, I've searched but I couldn't find anyone has symptoms like mine.

My car is 98 ka24de 120,000kms. Recently, the car had 5spd swap. After swap, CEL was on because shop forgot to change the ecu to manual one.However, after they changed it to 97 manual ecu, CEL was still on. They manually checked the code and they said it was code 77 which is rear o2 sensor. So I bought it and got it installed. But after that, CEL was now flashing. (it was stayed on before) So we thought it would be the mechanic forgot to turn the knob on the ecu to back position. Mechanic did even check the code for flashing CEL but there was no code showing, and I even plugged the OBD2 and still no failure code..

Sometimes it doesn't flash, just stay on, but most time it flashes... What would be the cause??..

And one more weird thing,. When I'm driving and if I release the gas pedal, the rpm goes down to almost 400 rpm and up to 1500 rpm. Then it slowly goes down to normal idle. It happens only when under load(while driving).

Can anyone help me out?

Thanks for reading!!

[csw1986]

anyone??~

[240sxdrifter93]

ive read many things about the bad idle problem and from what i can gather is that it could be the maf sensor or if you have a turbo your maf might be to close and cools down to much do to the increase in air flow, the same thing happened to my car to the point to where it would die everytime i let off the gass at a red light but i changed my cap and rotor along with the spark plugs and wires and it has not done it since but if you do that and it still doesnt work then i would try your fuel supply it could be a bad fuel filter fuel pump or bad injector mine used to loose a cylinder for a while and kick back in when it wanted ran with way less power and used more gas than if it had all four if you try these and they dont work then keep searching but if they work let me know what you did good luck

[csw1986]

I don't have turbo.

What I've done so far. I did check the code again (by myself) and I noticed the screw on the ecu wasn't turned fully counter clock wise which was on diagnositc mode.... I assume may be that was the cause of flashing CEL.

What is EGRC BPT valve? Anyone knows? and Where is it?