2002 Nissan Frontier, 137000 mi. I-4, Auto
I was having rough idle when cold, and wouldn't keep running without pumping throttle like crazy and then most times had to restart 3 or 4 times. Once engine reached operating temp, it did ok.
Light was on and Code was 420. so I replaced MAF, O2, and upstream sensor - light stayed on. Then found leaking valve cover gasket and fouled plug in #4. Code was 420 and 306.
After new spark plugs, wires, dist cap and rotor, valve cover gasket, runs smooth and fine AND all codes reset themselves, which the mechanic was puzzled about and could not explain.
BUT I still have rough idle on cold start and engine dies. AND if I bring it up to 3000 rpm and hold it, it stays there for 3-5 seconds and falls off and dies. And again, drive it a few blocks, warm it up, and it does fine, smooths out, and starts fine for rest of the day. Sitting overnight and idle problem returns. Also I started it today in 81 degree weather after sitting since yesterday and same problem.
What do you say? Remember, all codes are now cleared and no dash light.
I was having rough idle when cold, and wouldn't keep running without pumping throttle like crazy and then most times had to restart 3 or 4 times. Once engine reached operating temp, it did ok.
Light was on and Code was 420. so I replaced MAF, O2, and upstream sensor - light stayed on. Then found leaking valve cover gasket and fouled plug in #4. Code was 420 and 306.
After new spark plugs, wires, dist cap and rotor, valve cover gasket, runs smooth and fine AND all codes reset themselves, which the mechanic was puzzled about and could not explain.
BUT I still have rough idle on cold start and engine dies. AND if I bring it up to 3000 rpm and hold it, it stays there for 3-5 seconds and falls off and dies. And again, drive it a few blocks, warm it up, and it does fine, smooths out, and starts fine for rest of the day. Sitting overnight and idle problem returns. Also I started it today in 81 degree weather after sitting since yesterday and same problem.
What do you say? Remember, all codes are now cleared and no dash light.