hi guys, my frd's 03 ap1 got random misfired issue recently. At first, he replaced all his plugs and we all thought the issue was sloved. Last week, the light was back again. Same code and we decided to erase the light and see if it gonna come back on again. It didn't. We all thought that should be computer error or misread. Today, the light is back again. What could be the problem? The car currently has 66k miles.

we did some research online. what we think could be the issue might down to either value adjustment or the coil.

Let me know what you guys think, anything would help.

Thanks

 

valve adjustment

bad coilpacks

or bad crank sensor are some common items.

 

is there any ways for my and i to check those by ourselves? or might be better to take her to a shop?

 

If u aren't experienced with doing motor work I would only take it to a well known S2000 specialist.

 

Before taking it in, go buy a case of techron fuel injector cleaner at Costco. Run your tank bone dry, refill with non ethanol gas high octane, and add two techron treatments in the first refill. Then run one in each tank until you use up all 6. Let the CEL stay on - if the injector cleaner works, the light will go out on its on after the engine has run enough cycles without a miss. If you get a flashing CEL, stop driving immediately and start troubleshooting other things.

Same exact thing happened to me, and a 30 dollar case of injector cleaner nipped it in the bud.

After you run two tanks of treated gas through, if your CEL is still on, do a manual reset. If the code appears immediately again, it's probably not gummed injectors, or yours are so bad that they need to be removed and cleaned. A guy does it on here for 60 bucks.

It's worth a shot. Cheap fix if that's all it is.

Gas these days can be pretty bad. I always stick with Chevron or 76. Preferably no ethanol.