im new to this forum. after reading through a few threads, i think ive come up with the answer to my car problems, but just to be sure, i thought id start another thread and ask away anyway...

i have a 2002 Civic LX, 5 speed manual. its been a really great reliable car and i get excelent gas mileage. (33+/-) but this past summer it started hesitating and bogging down durring exceleration. sometimes when idling. sometimes it runs great (but not very often lately) its inconsistant.
sometimes i get a check engine light. sometimes it stays on, other times it flashes (especially when im excelerating and its bogging badly) and other times the light that was on will go away, even tho its still missing.
i do alot of highway driving, and when im going 75/80 and have to slow down to 60ish, itll bog and ill have to shift to a lower gear, which makes the engine race like mad, but at least its not hessitating anymore. it seems to run fine when the rpms are above 3Kish... city driving can be very frustrating. i have to rev the engine a little at red lights to keep it from missing, and when i go to leave, rev it up, put it in gear and rev it some more as i go or else itll konk out on me.
i took it to my local autozone, and they put a tester on it to read the code. they didnt have the greatest tester, but he said he was getting a reading that said that all 4 cylinders were missing. he said it was impossible, as the car wouldnt run at all. so we did a test/process of elimination by resetting the error, then i went around the block, came back and read it again. it pointed to 1 cylinder. then we reset again, and swapped the coils around (noting which one was giving an error) and i drove around the block again, then read the code again. the error stayed with the coil. so i figgured thats that. i couldnt afford a new coil then & there (and he didnt have one in stock anyway) so about a week later, i bought one and replaced the "bad' coil.
it made no difference whatsoever.
since then, ive experimented on my own, and i noticed that if i rearange the coils from time to time, it clears up the bogging, at least temporarilly. that is, until i gun it too hard or something, and once it starts missing, the condition stays. i also notice a strong smell of gasoline when i remove the coils to swap them around.
and yes, ive changed my spark plugs and checked my connections and the condition of the wires/coils/boots ect. its all good & clean.
i really dont think it has anything to do with the coils. im thinking i have a larger problem and the coils missing is a symptom, rather than the problem.
so ive been reading up on this forum, and its sounding like a bad FRONT O2 sensor.

my question is... what else could it be?
and WHY am i getting such huge price differences when i google the cost of an O2 sensor?? some are $40, some are $280!

any help would be MOST appreciated.

btw, tommorow ill take the car back to autozone and see if the code reads anything about an O2 sensor. i dont remember that comming up when we first did the check, but its worth another look. im not into fixing the same thing over and over again. (who is?)

thanx

 

sounds to me like a cps sensor, its a random misfire in all cylinders.

the reason the o2 senors are big difference in prices
cheapier ones dont come with a plug hook up, you have to cut your plug off the old o2 and wire it on the new o2, while the more expensive ones are direct plug in.

 

I was thinking the difference in price on the sensors was due to location/application.

I would recommend getting NGK sensor with OEM plug installed for your car.

 

today i went to Autozone and had the codes read. 5 errors: P0300 -P0304 random misfire, and misfires in all cylinders. but nothing from the O2 sensor or the CPS sensor.
the printout of the error codes also gave recomandations on what the problem might be, but it was awfully vague... the only one that pointed to anything was the random misfire code, and it included MAF sensor faulty, and the O2 sensor. so i bought the O2 sensor. exact fit for $60 w/tax.

it made no difference whatsoever.

so far ive spent $120 and have gotten exactly nowhere.

the CPS sensor is around $80. (and i cant seem to find it on the car. id at least like to check the wires before i blow another small fortune on a wild guess) and i dont know what a MAF sensor is...

any recomendations??

 

I would strongly recommend cleaning the Idle Air Control Valve.
Carbon build up will cause it to malfunction. The low idle is an indicator that it may be malfunctioning. When the outside temperature drops, this valve is more important. I cleaned mine on my D16Y7 engine and the performance improved. The random misfire codes P0300 - P0304 stopped. The idle operation went back to normal. You should have a D17A1 engine. The idle control valve on my car is part of the Throttle Body system. I removerd it fronm the car and removed it from the throttle body I then cleaned it with brake parts cleaner and paper towel to remove all the carbon. Check to see if your engine uses the same type of idle control

 

not entirely sure on your particular year but but does your ecu go into backup? same thing happened to my car it would randomly bogg down. my ecu light would flash but not give any definite codes. I replaced my o2 censor and ecu because it would go into back up and id have like 40 percent power. I looked at all my sensors and realized that wasn't the problem. I then for kicks and giggles replaced my spark plugs and it hasn't happened since. funny thing is they didn't look too bad. Id start there also look for an arc in your plug wires and throw a timing light on your car to see where your at. good luck.

 

Clean your idle air control valve.

 

Ive got the same car with the same problem, mine is a ex. but i had a ruff idle so i cleaned the idle air control valve, cleared up my idle but car still misfiring and running lean. Ive also got the same codes???? what else could it be?

 

i finally got around to cleaning my idle air control valve. it was very dirty. i spent about an hour spritzing it with brake cleaner and scrubbing it with Qtips (making sure not to leave any cotton behind). when i put it back together and tested it, a big puff of white smoke came out the tailpipe, the "engine" signal came on and stayed on, and the idle rev's up and down up and down...
so obviously i did something wrong!! HEEELLLPPPP!!! its WORSE!!!

 

unhook battery then hook back up, and start car again