free_refil

So I noticed after filling up that the car started to idle very rough. There was a huge loss of power, my check engline light came on, and my gas mileage went down to about 130 miles for that tank!!! I thought for sure that filling up would have maybe got some crud from the bottom of the tank into my fuel filter and clogged it. But I wanted to take it to Auto Zone and have the code checked anyways. The following codes were present: P0134 (A/F sensor 1 heater system malfunction), P0300, P0301, P0302, P0303, P0304 (all cylinder misfire/random cylinder misfires). I did some research from the forum and decided it was probably the A/F ratio sensor before the catalytic converter. But before I spent the $210 that it costs for a new one, I decided I'd check the ignition and fuel system before, as getting no spark or insufficient fuel could probably throw the A/F sensor off. Luckily for me, the first thing I decided to do was to change my spark plugs and check for spark out of the coils. I checked all my coils, all produced spark, then went to change the spark plugs. The first three looked normal, but when I pulled the third coil, I noticed it was COVERED in soot and the entire chamber was covered in soot as well. Also, when I went to take the spark plug out, THE ENTIRE SPARK PLUG HAD CAME UNSCREWED FROM THE CYLINDER HEAD!!! I was like OMG! Also, the metal prong that the spark jumps to had completed dislocated from the spark plug and is probably somewhere's in the cylinder or hopefully left through the exhaust. Anyways, replaced that spark plug, and all is well. Just wanted to write down my find in case anybody comes across these series of codes and doesn't want to spend the $200 first when it could be an ignition problem!!!

BlueEM2

iTrader: (1)

Nice find!!! Hopefully that piece is long gone and its always good to do what you did and research before you go and spend the $$$... I don't know how many people have changed sensors that they could have cleaned just for an example.

ashokudu

how did u check if the coils were ok? i have a similar problem.. rough idle, and poor gas mileage.. except i dropped from 38 to 28 in a gap of one tank of gas.

only thing i did is i went from good year triple tread to good year integrity and my gas mileage dropped 10mi per gallon. i do not think change of tires wud cause that much drop and top of it i got it aligned as well.

checked spark plugs... and did change them at 120K to NGK PZFR6F-11 (OEM). Now i got 130K. Did gap them to honda spec 1-1.1mm.

any help will b great in this matter... only thing now is clean the a/f sensor & may b fuel filter replacement.

no check engine light either. oh yea engine is a little noisy...

ashok.

trents

Just had the "Random Misfires" issue last week. P0300, 0301, 0302, 0303, 0304 codes. Turns out it was my E3 spark plugs with 60k on them. I switched back to stock & problem solved.