car: 1988 Crx si
engine: dohc zc
ecu: pg7

This engine light has been an ongoing struggle. Its been on for the past couple of months and after 3 used o2 sensors and messing with wires under the hood, its still on. Usually it will come on after 30 or so minutes of freeway driving, but lately its been coming on even when the car is parked and idling. I hate the way that yellow-eyed monster shines brightly staring at my face. Its worse at night as it lights up the entire cockpit. So this weekend I decided that I must kill that light. So the first thing I did was run a wire from the O2 pin c-16 from the ecu directy to the sensor. After 10 minutes of idling, the light comes on. So I go out and buy a brand new O2 sensor. After driving the car for about 10 minutes, I'm stoked cuz the car feels extra smooth and running like a champ. However, sure enough, a few minutes later the evil eye comes back on. At this point I am pissed and park at the side of the road. After cooling off for ten minutes, I'm as frustrated as can be and take my piece of **** car home. I try another ecu, same result. I just want to take a screwdriver and drive it into that light, eliminating it forever, and that damn ecu led too. Pls. help me before I turn mental. I'm driving my civic tomorrow.

 

Does your car burn oil or use coolant? both can kill an 02 pretty quickly, along with cheap gas or "horsepower booster" additives

 

no. my car retains coolant and oil. it runs fairly well except for that retarded light.

 

Check your grounds.

 

where does the o2 ground to? its only 1 wire.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Carsonsurfer &raquo;</TD></TR><TR><TD CLASS="quote">where does the o2 ground to? its only 1 wire.</TD></TR></TABLE>

Through the body of the sensor... so the 'header', but be sure that all your grounds are good, poor grounds can cause sensor issues.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PURPLETERROR &raquo;</TD></TR><TR><TD CLASS="quote">Does your car burn oil or use coolant? both can kill an 02 pretty quickly, along with cheap gas or "horsepower booster" additives</TD></TR></TABLE>

Not only that but try some injector cleaner...running to rich can toast them too. Also be sure to check your PCV valve and maybe clean your breather hose/tb.

 

So do guys think I should remove my brand new o2 before I do any damage to it.

 

The ecu AND the O2 are working properly. Your running too rich and under part throttle open loop driving it cannot keep your car around 14.7 a/f ratio. If it is coming on really fast now you may have messed up the connection but what you described earlier is a a/f ratio problem.

A cel will tell you two things:
The sensor is not there = no reading.
The sensor is there and is getting an improper reading.
I really hate it when people bitch about the CEL when it is in fact doing it's job.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DohcVtecCrx &raquo;</TD></TR><TR><TD CLASS="quote">The ecu AND the O2 are working properly. Your running too rich and under part throttle open loop driving it cannot keep your car around 14.7 a/f ratio. If it is coming on really fast now you may have messed up the connection but what you described earlier is a a/f ratio problem.</TD></TR></TABLE>

Yes, I think it is true that the O2 sensor can only adjust for about a 15% correction factor, so you may be running overly rich to the point that the 02 can't "sweep".

 

change ur pcv valve and clean ur injectors and see if that helps

 

So my next goal should me leaning out the mixture.

 

yes

 

do you have pics of this?

i have the EXACT same problem. Do you have the problem of the jumping idle too? I do and i've replaced the O2 sensor and it was fine for maybe 2 days of driving then the CEL came on again.

I'm gonna replace all the vac lines this weekend if you can gets pics of this stuff i'd really love it. I'll also replace some of the easy gaskets if needed.

BTW what car did you order the gasket for?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mr_valentino20032000 &raquo;</TD></TR><TR><TD CLASS="quote">do you have pics of this?

i have the EXACT same problem. Do you have the problem of the jumping idle too? I do and i've replaced the O2 sensor and it was fine for maybe 2 days of driving then the CEL came on again.

I'm gonna replace all the vac lines this weekend if you can gets pics of this stuff i'd really love it. I'll also replace some of the easy gaskets if needed.

BTW what car did you order the gasket for?</TD></TR></TABLE>

Here is a nice diagram of the vacuum lines for a zc:

This site lists the zc parts and part cross reference.
http://thenew.gamesbbs.com/~dm...0List

CORRECTION: The gasket that I needed and ordered was a throttle body gasket which is from an 88-91 Crx Si.


Modified by Carsonsurfer at 1:55 AM 8/5/2005

 

awesome!

thank you very much. i'm gonna run to lowes in a few to buy some new hose since i think the 5/16ths stuff might be too thin

 

Did you solder the o2?, if you did i would undo it and try jus twisting the wires together, the solder can add to much resistance and throw the reading out of whack, i have had a prob like this before and it fixed my prob.

 

there might be an intermittant connection between the sensor and ecu, run a new wire from the sensor to the ecu just to be sure

 

I know you said that you tried another ecu,b ut did you reset any of the ecus after the code when you replaced the sensor. I was getting the same code, tried different sensors and finally bought a new one and the code came back up again after about 15-30 minutes of driving, pulled the hazard and ecu fuse under the hood, and never had a problem since.

 

Yes the third 02 sensor was soldered near the ecu plug where the new wire joined a small piece of wire going into the ecu connector. As for the other ecus, yes they were reseted and the code came back. I checked the PCV valve and it was totally wasted with all this gunk in it. So I'll be replacing that too. I bought one for an 89 integra at autozone for 2.99 and it was a little larger than the oem one i pulled out the intake manifold. I hope it'll be ok. My new throttle gasket is supposed to come sat. So I hope all my vacuum lines will be ok after I plug them all back in--esp. the map sensor.

 

UPDATE

After redoing my vacuum lines, changing the pcv valve, and throttle body gasket, the code is still there. Now the car is beginning to bogg horribly during regular driving. As i step on the gas, the rpms would go down to zero. I would go nowhere as i here the intake groan. I have to ease off the gas and hope the car will respond. Anyway, I changed the rotor and that didnt do anything. It only boggs when the engine is at normal operating temperature. Could it possibly be a bad map sensor even though i'm not getting a code for it?

 

woww. bump for this guy.

i've been having some of these issues to. just not as much as u

 

any one out there with any ideas as to how i can rid my rex of this engine light and bogging issues. im desparate

 

My crx has more mood swings than a bitch PMSing. Yesterday, it was bogging s badly that is was virtually undriveable. Today, I drove the crx around today and the bogging mysteriously disappeared. So I was like, "OK, cool." So I decided t have a look under the hood and found that the two thermostat ground wires were screwed into each other. So I separated them both and screwed them separately next to each other. After this, the car ran noticeably smoother. The car is now running excellent! Unfortunately, when the motor is fully heated, that ******' light still comes on. I don't get it, it runs perfectly now. Maybe I just need to learn to live with it

 

I am absolutely stoked! The engine light is now gone. I rechecked the wire that I ran from the o2 to c16 on the ecu and it came apart. So I repaired it and expected the light to come on again after I drive it for a while, and it stayed off! So the culprit the entire time was the bad ground connections and the wire that for some reason came apart after i just sodered it. After all the other things I've changed in trying to eliminate that code along with actually fixing the problem, my car is running better now than ever. The saga has now been concluded and it ends in a happy ending. So now I just want to take this time to thank the honda-tech community for all your help and support. Sniff...You guys rock!!!