Alright, I just put a turbo in my EX civic. Its a 96 with 121k on it. I recently installed the a/f guage in my car but when I started the car nothing came on but a dim lit RED led on the far right side. I mean DIM. It would just sit there and flicker at me and do nothing. Thinking I got the wrong wire on the ECU, I tried hooking it to the secondary O2 sensor coming out of the floor, then I read how you cant do that. After that I ran it straight off of the primary O2 sensor coming off of the manifold (white wire) and still the same thing. So after doing that I figured it was the right wire and kept it installed. Driving home after that it just came on all of a sudden bright as if it was installed right. BUT, only the bottom RED led came on, and it would flutter between the last 2 led's on the red side. Now i've seen other peoples guages and they "scan" around from green to red like crazy. Mine wont even scan, it just sits there and blinks every so often. OR, i'll be cruising along with it in gear, and i'll let my foot off of the gas, and then press down again a little bit, and the led will bounce up to yellow, and fall back down to red. Now i know im not running lean judging by my spark plugs (which are colder heat range NGK) are black. I know im running rich from the smell as well. But im wondering if the guage is bad, or if my o2 sensor is bad. My friends who have A/F guages, when they click their key forward powering everything on, the guage will sit at green and not move until they crank the car. Mine on the other hand doesnt really even come on when i click the key forward. So maybe the o2 sensor is bad, or maybe the guage is bad any help would be great.

 

allow my to fix my post, i didnt seem to have my L and R written on my hand that day, the red LED is on the LEFT side of the guage....who know what a red LED on the right side would mean. hahaha

 

Someone please answer this. I have the same exact problem, but mine stays at rich (green). I had a shop that will remain nameless install it and they said they didnt know what to do.

 

got a voltmeter? That will tell you if its the o2 or the gauge...if the o2 was that off would assume the engine would have a hard time running at all. Everything grounded right?

 

I had the same problem with my first autometer guage...it just lit up that last red light..just stayed there....took it back to the shop...showed them it was hooked up right...and didn't work...so after lil bitching...I got a new one..thank god it worked. But I would test it with a voltmeter before i start making conclusions

 

You need a voltmeter (DMM)...plain and simple. To troubleshoot this problem, you need to be able to measure voltages...and no amount of feedback from this forum is going to get you that reading.

I would suggest you pony up and get a Helms and voltmeter.

Now, as far as O2's are concerned...they need to heat up to at least 600 dgr F before they begin 'scanning'. On my stock 99 CX, in the morning time or any time the O2 is cold, it just sits there at about .9V....which to your A/F gauge would mean green lights should be on.

Can O2's be 'bad' and not throw a CEL....yes. I had it happen to me not to long ago. I had 120k miles on the clock (original O2) and its time was just up. It wasn't crossing very fast (yes, O2's do get lazy...hell, they do have a recommended service interval of like 60k miles...but for $140 bills...people just wait till they see a CEL come on) anymore and left my engine in a wierd state of tune.

 

O2 sensors do not wear out... there is nothing inside them to do so. Clogging or fouling is the most likely cause of one going bad. Either from a blown head gasket (anti-freeze), running to rich or lean, burning to much oil, or gunk getting on the outside of it, and blocking the holes it uses to read outside conditions. Just to name a few of the things that can go wrong with them. Some have been known to last a lifetime of a well maintained car.

 

im going to buy a new bosch o2 sensor tomorrow and find out if its the sensor, or the guage...either way figure I need a new one anyway, the old one has 122,000 miles on it....yikes!

 

Please post the outcome. Thanks.

 

ok, so I replaced the O2 sensor, and the damn thing still doesnt read. I also found out that my original o2 sensor was CROSS THREADED into the down pipe, so now the o2 hole is stripped...ahhh, but I was able to thread the new o2 in right and seal it. Now I have to check the guage. Im going to put my guage in my friends car who has one and see if it works. I'll post the outcome.
cross threading is bad
cross threading is bad
cross threading is bad
cross threading is bad
cross threading is bad
cross threading is bad

 

ok I finally broke down and went and bought a new guage at NOPI, and guess what.......IT WAS THE GUAGE! stupid summit racing sending me defective ****. oh well, all is happy now in the land of A/F guages. Im sending that **** back to them with a nice little note.

 

Sweet! Ive got store credit at my friends shop. Im going to get a new guage and try that. Thanks for posting the outcome.