95typeII

My check engine light has come on 3 times in the past 4 days. The moment it does, my engine hesitates to accelerate during regular driving. It always occurs within the first 5 minutes of driving then continues until the car is turned off. Im not sure what it could be considering I installed a new idle control valve within the past year, and that wouldve been my only guess.

Any ideas or suggestions?

 

bl420

check what the code is by jumping the connector at the ECU and reading the code. theres info in the Newbie FAQ

off the top of my head its probably something fuel related. maybe its your o2 sensors.

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95typeII

Thanks, bl420. I finally went to my buddy's shop and seems to be the O2 sensors. Ill be replacing those within the week. Im just glad it wasnt anything major.

bl420

no problem... btw did you order them yet? you can get them cheaper than dealer price if you go to sparkplugs.com

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95typeII

I've searched sparkplugs.com several times and havent found any O2 sensors.

Alperovich

eer 02 sensor huh and its running pourly/hesitating

sounds like fouled spark plugs not a bad 02 sensor.

did they hook up a lab scope and watch the output of the 02 sensor?


100% sounds like the plugs aren't firing right, sending raw fuel into the exhaust stream setting off the 02 sensor.....

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~Alex

94 GS
MLS Bar; FUT rear ties; ADDCO rear sway bar; Blackend Engine Damper; EBC Yellow pads; D/S Rotors; Enkei EVO5's
Alpine HU+Speakers; 93 front bumper; Matte Black grill; Stromung axle-back 2.5 tips

bl420

its going to come up spark plugs but on the right hand side. there will be a drop down box so you can select o2 sensors.

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bl420

im pretty sure that OBDI cars dont have a downstream O2 sensor. i dont think raw unburnt fuel would set off our primary O2 sensors considering the fact that hondas run rich... pig rich.

the primary o2 sensors only trip a CEL if theres a problem with the heater circuit or the signal circuit.

on OBDII cars its a little different where the secondary/downstream o2 sensor detects if there was fuel flowing past the catalytic converter. tripping a CEL would tell you that theres something wrong.

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Alperovich

wrong. unplug one of your coil packs and drive around for 20min, you'll throw a code 02 sensor.

A downstream o2 sensor just looks for Cat output.

a upstream adjusts for a/f coming out of the cylinders. If there is too much fuel it wont be able to adjust itself after sometime quickly throwing a 02 sensor code.

I've ran on bad fueled plugs b4, it does infact throw a code.

First step in, any sensor check engine light, test the sensor.

Check the plugs b4 getting the o2 sensor.

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~Alex

94 GS
MLS Bar; FUT rear ties; ADDCO rear sway bar; Blackend Engine Damper; EBC Yellow pads; D/S Rotors; Enkei EVO5's
Alpine HU+Speakers; 93 front bumper; Matte Black grill; Stromung axle-back 2.5 tips

95typeII

Found it, finally! Thanks for the help.


I doubt its the spark plugs cuz if it were i believe it would be constant and it doesnt always occur. Also, I've been runnin kinda rich for some time, hence me leaning towards the likely cause being O2 sensor(s). Furthermore, my mechanic said since the code doesnt stay on permanently, it also leans more towards it most likely being the O2 sensor.


I might just change the spark plugs as well as both O2 sensors since they are the original ones and its been almost 2 years since I changed the spark plugs, even though they are Iridium NGKs.

Thanks for all the help, fellas.

bl420

i dont have coil packs... :-D actually i do but just one

i understand what you're saying but to me i just think that a fouled spark plug would just run shitty from the start.

i've had a bad spark plug wire on my integra that would cause the same problems where it hesitate and sound like its backfiring. but no codes or anything thrown.

so i guess the OP will just have to test each component. and it wouldnt hurt to see the condition of the spark plugs anyhow so might as well do that.

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Alperovich

guys, what he is describing IS what happens with fueled plugs.

while the engine is COLD, its running fine.

warmed up, starts to hesitate. usually VERY noticeable 1250rpms to 2500rpms. When it gets real bad, it'll start to misfire and the whole car will shake. I've been down this road, from when my ecu wasn't tuned right and I fueled my plugs.

Check your plugs, first. See their condition. THEN go onto TESTING the O2 sensor.

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~Alex

94 GS
MLS Bar; FUT rear ties; ADDCO rear sway bar; Blackend Engine Damper; EBC Yellow pads; D/S Rotors; Enkei EVO5's
Alpine HU+Speakers; 93 front bumper; Matte Black grill; Stromung axle-back 2.5 tips

imsotype2

I have this problem also. I shift into 2nd gear and the car does a slight hesitation and I was like WTF because I just changed the spark plugs 2 weeks ago. I think I'll go ahead and get the 02 sensors replaced ASAP. My check engine light didn't come on, but I'm sure it is something with the emissions

95typeII

I replaced the O2 sensors and had the EGR system cleaned out. Problem solved!

Thanks for the advice though!

legendfire

ive got the same kind of hesitation, feels like the clutch is slipping, but its almost brand new. its from 2k to 3k rpms. its not throwing a code. any ideas? not meaning to thread jack.

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