My AP1 w/ 91k on it just had CEL and codes 1399, 1301, 1303, 1304. Solved by step one in this write-up, the spark plugs were bad. Thanks to Science of Speed for figuring this out for me

 

So I just installed my new exhaust with a TP. I get off my block and I get the blinking engine light and the engine was missing. I push it back down my street and pull the plugs. They all look fine, no foul. I have the P1399 code. Could I have not tightened down the O2 sensor enough to trip this cel?

 

^^^^^Ok fixed it. I put new plugs in and then swapped all the coil packs from another car. Cleared the code and it purrs. Let it warm up then took if for a spin. Perfection, no cel or misfire. Then I swapped back in the old coils on at a time until the misfire appeared. It was only one pack, Picked one up at the dealership. (Not cheap) now I'm back in business!

 

my ap1 with 43k miles had been smelling like fuel inside the cabin for about a week or so. I would open the hood and look/smell for fuel leaks and saw none, but oddly enough there was a strong odor inside the car.

Last night the car threw a CEL and started idling funny. I ran the scanner on it and it said misfire cylinder 3.

Checked all coils for spark, all were good. Cylinder 3's spark plug was black as hell and wet with fuel (which leads me to believe the injector is at fault....right?)

Auto parts store was closed so i couldnt get new spark plugs and a new injector. Am i on the right path?

I'm thinking maybe that one injector has been leaking, causing the smell of fuel, and might have wet the plug as well causing the misfire? I hope its that...

 

What DTC do you have?

 

303...or whichever one denotes cylinder 3...

 

I have no spark in cylinder 3 from the coil itself. No idea why. I've changed coil packs. spark plugs and even cut the wire for a new one....

 

I don't have any DTC's no pending DTC's no CEL's(checked with my teacher's $3,000 Honda scanner) replaced the coil packs, the spark plugs(they were light brown at the threads with grey tips), cleaned IAC, replaced O2 sensors, compression and leak down are good, and yet my engine has a slight miss during idle. It idles fine otherwise, very smooth, but I can hear a slight miss that happens randomly(car exhaust burbles normally but randomly it sounds like one cylinder doesn't fire). I checked all the wires, and coil pack connections, they all seem to be doing their jobs. The problem is most prevalent when I first start the car, once it's up to operating temperature it still does it but it's much less frequent. Is this normal? It's a 2002 AP1 with 130k miles, I have a Berks 70mm header back, and a CT icebox, filter was replaced in December of last year, and I cleaned it two months ago.

 

awsome write up, just what i needed as just 3 days ago, my CEL light came on and i think its most likely due to a misfiring cylinder like last time :/ spending like 5k on this car just to get it running makes me really regret buying it now..

 

I recently changed my car to a 70mm berk and a couple days later got a cel. Says it was 1399 and 0303. I changed the plugs and swapped coil pack 3 with 2. Now I get code 1399, 300, 301, 302. Any thoughts. Was thinking to tq down the plugs more and try some fuel cleaner.

Btw, plugs looked dirty, plug one had oil on top which might be from valve gasket.