silverbullet9626

I have a 96 civic dx with a jdm B16a sir II. It has been swapped for almost 11yrs now with the jdm harness and ecu. The issue im having is while driving at any speed it will shutter and if i give it more gas it has no power, while im still in the gas the power comes back and it constantly does this. My local honda guru said to change the O2 sensor, its not giving any cel for it so i decided to unplug it and drive it to see if there is a difference before buying a new one. It forced a code for the sensor and stopped the issue so i got a new one. 3 months later it started back up so i repeated the previous steps. When i pulled the new sensor out it was caked with carbon and i managed to get it replaced under warranty but it only lasted 3 weeks and today it started to idle surge for a few seconds. Still no codes unless i force it and it will run better ish. My local guy thinks it is running very rich and loading up the sensor with carbon causing it to fail and may need new rings. The engine is 100% stock except for the intake, header and catback no other modification has been done. The only changes ive done in the last yr is going from a 4-1 header to a tri-y and he said that wouldnt cause it. Last november i did plugs, wires, cap, rotor button, and fuel filter. My gas milage has dropped significantly since november which explains running rich. I dont see how needing new rings will cause it to run rich nor any of the recent changes and cant think of any reason why it would randomly start doing this. If anyone can help me out it would be appreciated, she is my daily and i need to get it back to its reliable self. If it helps all 3 sensors were denso brand and the plugs/wires are ngk, dont know who makes the header, and the cap/button are duralast.

sumdewd

Is it burning oil constantly? This absolutely would explain the O2 fouling issues. Have you checked fuel pressure yet?

Have you tested for a hot spark? I've noticed a huge uptick in threads about failing coils and igniters, and I've personally replaced several on my family's cars. It looks like 20-30 years old is where they start to go. There was another thread recently about testing those suckers. I'll see if I can link it to you in a little.

Edit: Found the thread: https://honda-tech.com/forums/honda-...ather-3319888/

mk378

Remove the spark plugs to see if they are all black or just one of them.

silverbullet9626

Its not burning oil too much for an engine with around 150k on it, maybe a quart and a half between changes and Ive done that a 3k religiously. However the back bumper is covered in black soot and you can smell that it is running rich at idle which is kinda low, maybe 550-600 rpm. My mpg has dropped from 30 plus to 25 in the last few months as well. I have changed the coil twice since ive had the engine in 08, and put new ngk plugs and wires in a yr ago.

muellersfan

Compression test the engine when it's fully warmed up.

Test the fuel pressure regulator.

Also check for an exhaust leak around the primary O2 sensor.