So I had replaced the o2 awhile back, maybe 4-6 months ago with a non-factory, hoping to save money, which fixed the check engine light. Thought I was good! Then about two weeks ago started to get the light again, not every start but most. But sometimes not. Then it started to go on always, which is the case now. Took her to my favorite independent mechanic, who usually fixes stuff fast and relatively cheaply. He first suspected the o2, being non-factory and all. But after 2 other Honda oem units, he decided that's not it. Now he wants to take it again and keep it for a day and figure out what's up. Guessing wiring harness or ecu. He stated it's really a weird one...

Anybody have thoughts on this? I trust him, but wonder if there are some interesting solutions for this. Meantime may look around for an ecu...

Thanks, and yes did my searches.

 

What cel codes are you getting

 

https://honda-tech.com/forums/acura-integra-6/ecu-abs-codes-here-978933/

 

Mechanic didn't say, and when I tried myself oops fried a fuse. His writeup says 02 sensor.

Anybody hear of an ecu dying? Or partially? Thinking of getting one myself, trying to swap and see what happens.

He said the aftermarket 02 sensor may have caused problems.

 

Use a scanner to check for your check engine light. Or try using a paper clip on the fuses and then see what code its throwing. You blew a fuse while doing that? Are you sure u put in the paper clip in the right fuse?

 

Did you read the damn link I posted?

 

How the F did you pop a fuse checking for CEL codes? No scanner is required. Just jump the 2-terminal blue diagnostic connector under the bottom right of the glovebox with engine idling and see what codes the light flashes out for you.

on anybody merely throwing parts at a car to fix a CEL without actually pulling the trouble codes to see what the problem might be.

 

Ouch, easy, trying to get it right here. Well, dummy I am, didn't realize there are two terminals that live in the green boot thing. So I tried to do the shunt in the three lead terminal...which is what blew my fuse...

Now I have it right, after finding the "real" ecu terminal. So that produced a 41, which according to what I read is 41 Primary oxygen sensor heater. One thing is that my cat is probably dying, so once I get that replaced wonder if that will clear my cel. I read that exhaust system issues can be a cause for this cel.

I was tempted to just get another ecu, maybe a chipped one just cus it would kinda fun.

Thanx for bearing with my newbocity...but I am learning, good thing.

 

What make and model is this?

What ecu are you running?

There is no reason to get a chipped ecu for a bone stock motor.

 

95 gsr, greddy axle-back, 4-2-1 header, soon a Tanabe or? short ram, and thought as long as I was going to try a new ecu anyway, try one that's chipped...yeah, probably dumb. Oh and haven't installed a fuel rail and throttle-body that I recently got, not that I expect too much from that.

 

You would need a chipped p72 ecu if you wanted to go that route since you're still running the stock GSR IM with the secondary butterflies.

For now I would just stick with the stock ecu.

 

Yeah, I kinda knew that was what the people who know better would say. Plus I kind of doubt an ecu would throw cel by itself? Would be nice if I had a known good to plug in.

The mechanic tried some oem sensors, didn't clear the cel. He said the generic I had possibly damaged the ecu?

Anyway, funny thing is the car runs fine. In fact I got great mileage this past week, took it on a few trips over 100 miles, getting over 30mpg.

Thanks again for the teaching!

 

If your ecu was fried then your car would obviously not start.

If your car is throwing a CEL that you can troubleshoot and get a code for then most likely the ecu itself is fine. I've never had an issue with a stock ecu.

Only issues I have experienced with are chipped ecu's with resistors and transistors taking a crap. Could possibly occur in a stock ecu but not as often.

I would definitely get a new cat converter and an o2 sensor.

 

Ok, well getting a Magnaflow cat this week. I assume I can get oem sensor at the local O'Reillys or such?

 

They're not OEM since you are not purchasing it from Acura, but they work the same.

 

So any reason to go to the dealer, except to pay more? I know some people believe in only factory parts. I will pay more if it will buy reliability. But loving to save money to buy more fun stuff, like intake or manifold...

 

No there is no need to buy an OEM o2 sensor. The one's from Napa and such work the same.

Factory parts as in timing belts and bigger stuff.

 

Good to know. I was looking at some timing belt kits on the 'bay, maybe should scale that idea back. Who makes the oem belts? And thanks for taking the time. I sure love my lil blackie. She's been good to me. 150k and hope to go another 100 at least.

 

an oem cat uses much higher grade metals than an aftermarket unit. that's why they cost more and last much much longer. but that's beside the point. your cat isn't the cause of your cel, though a bad cat may result from it. you'd have to run a gas analyzer to find out if the cat is operating correctly since your car is a 95 and doesn't run a secondary o2.
it is possible that the ecu is the culprit. what your mechanic wants to do, or probably will do, is check for continuity from the o2 connector heater pin to the ecu connector heater pin. if continuity does not exist, the problem is between the ecu and the o2 connector. if it does exist, the problem is either in the ecu or the connection between the o2 sensor and o2 sensor connector

 

Yeah he wanted it back for more testing. Debating going that route or a more diy, where I learn and get more experience.

 

I smell ebay header, useless fuel rail, and tb that'll degrade current performance

Don't expect anything from it except minor bogging

 

not all that difficult. just need a multimeter and wiring schematic for the o2 heater circuit. did you use a universal o2 sensor? or did it come with a vehicle specific connector attached? because if it was a universal one, and you got the wires mixed up, it could damage the circuit. and it would actually take some time to do so. i'll bet that's what happened, since your mechanic hinted it as well. could be the reason why you were getting bad mileage too. that would all make sense. but then, that's just based on theory. test the theory and find out

 

Power for 02 heated sensor is supplied by the PGM-FI Main Relay, [injector relay output yellow/black] the ground, [orange/black] is supplied by the ECU/ECM, [02S HTC].

I would check continuity of the two leads, [PGM-FI Main Relay to 02 sensor, ECU/ECM to 02 sensor] with a multimeter, you can also test for power and ground at the sensor, engine running. 94

 

Header is DC, I know it's not the best, but carb legal is nice and it doesn't drag...yeah agree fuel rail probably won't do anything, the tb is an Erick's, thought they were pretty good. Figured would be fun to try these out, and if it's not going right pull them. Part of the fun. And learn along the way!
Finally after 30 years, getting under the hood and really becoming one with the mechanicals, one stumble at a time.
Thanx.

 

The o2 is a plug n play, didn't need to splice. Doesn't mean it's the best, to be sure. So the circuit, assuming it's damaged, is that internal to the ecu?

And is el crapitan in reference to El Capitan? Like just above SB? Nice spot, used to drive through daily.