check engine light, running rough

check engine light came on, not running any different, check all fluids ok, next day engine running rough, sounds like one cylinder isnt firing, get tune up which replaces fuel filter, distributer cap & rotor, etc. pulled codes for #4 cylinder misfiring, they suggested either replacing the injector or possible computer malf., took to another shop to have injector replaced. still running rough so they switched injector #1 with #4 and it runs fine, cleared codes and I was on my way. later that day check engine light comes on again. not running rough but when it first happened it wasnt untill the next day that it began. anyone else have the same or similar story? and any suggestions on what to do if it does start up again?

check engine light came on, not running any different, check all fluids ok, next day engine running rough, sounds like one cylinder isnt firing, get tune up which replaces fuel filter, distributer cap & rotor, etc. pulled codes for #4 cylinder misfiring, they suggested either replacing the injector or possible computer malf., took to another shop to have injector replaced. still running rough so they switched injector #1 with #4 and it runs fine, cleared codes and I was on my way. later that day check engine light comes on again. not running rough but when it first happened it wasnt untill the next day that it began. anyone else have the same or similar story? and any suggestions on what to do if it does start up again?

I had two problems in solving symptoms like yours. First the light came on due to the evapoartive canister valve. I had trouble filling the tank, pump would stop like it was full or not shut off and over flow. The evaporative valve was easy to replace for $28. Next I went to Sears and got an "OBD II Car Chip" for $60. The Chip gives error codes and allows you to reset the check engine light. Now my light was off, could fill the car normally but still idle rough at operating temps.
To find this problem I lifted the hood and listened while engine was on and warm. If you hear a hissing sound like air leaking from a tire you have a vacuum leak. Common leak area for 4 cyl Altima is the intake manifold gasket. The hissing sound will come from the rear of the engine. $400 at a dealer to repair. My second Nissan with the same failure.

Had the same problem with the check engine light and rough idle, Nissan dealership checked the computer and it said misfired in 4th valve & 3rd valve, which happened several times. Could get it to duplicate at the dealership. The coolant keeps going down, 36,000 and it turns out it's going into the engine. Doing Lemon Law now

Remove EGR vlave and clean. remove and clean injectors, check your sprak plugs and gap, distributor cap and rotor. Vacuum leaks can cause alot of problems as well.
I am sure it something that is overlooked and probably something really stupid. That is alsways how it has worked for me.
I have had this same problem before and that above is what i did at one time. never had another problem. dont know which one fixed it but its fine now. I also replaced the vacuum hose that goes to the egr valve.

I doubt it’s the same problem…. But you could try it just for the heck of it (expensive heck though) replacing you whole distributor. I had a problem where ODB II would show the knock sensor error code, we replace the sensor, car started and worked fine until it really warmed up and then would start misfiring at ~ 3,000 rpm and sometimes die all of a sudden. Tried multiple things but distributor was the last thing we thought would go wrong. Nissan has a TSB for “distributor rebuild Program” whatever that suppose to mean, could not get a straight answer from the dealer, but the fact that they have some “program” related to distributor, tells me it was/is a piece of junk. So we replaces the distributor and it’s running fine now…. Good luck.

Oh boy, you won't like this. I had the problem exactly as you described, except check engine light would go out at low RPMs (limped home on the freeway at 58mph in 5th). Turned out to be the throttle body required replacement. $900, but emissions are covered by law for 70K miles. My Altima had 69,467 miles on it. Lucked out on that one.