02 senors

[riden2low]

Got a 95 ATX that the engine light went on. Pulled the codes and got a 173 so I went down to Autozone and picked up a pair of Bosch and got them installed. Still getting the codes. The engine light comes on after the car warms up. Tried to do a search got all kinds of answers. Bought the car a year ago and this is the first time we have had any problems.
I own a 93 ATX too and had similar problems and the 02's took care of the problem on that one. On the 95 I took and sprayed carb cleaner just about every where thinking there is a leak but nothing. So sort of stumped at the moment

 

[SHOYAY]

Make sure the O2 sensors are fully plugged in, I know sounds dumb,but. Make sure the wiring for the O2 sensors are good,especially the wiring where it runs near exhaust. And, did you erase the codes after you put in the O2's? You can try unhooking the battery for 10 minutes and then hook it up and drive it.

 

[riden2low]

Thanks SHOYAY. After thinking what you said I did another check. Damn, the front one looks to be not all the way plugged in. So as soon as I get some coffee in me going to jack the front up and take care of it and hope this is my problem. After what you said, I was up before the Sun came out looking at that thing.

 

[riden2low]

Well no such luck. The engine light comes and goes. Get 173 and 177 code. Got the battery disconnected to try again. Got an extra intake and taken the MAF off and put it on the 95 to see if thats the problem. Just making stabs in the dark at the moment.

 

[riden2low]

Still getting the codes. But strange, when my 93 did this the engine light stayed on. The 95, the engine light comes on after it has warmed up and then is comes on and then goes out at random. Connections are fine. Just scratching my head at the moment.

 

[NP SHO]

How long did you leave the battery disconnected for? If you are using the paperclip method to read your codes I believe you can also clear the codes by pulling the paperclip while in the code reading mode.

 

[riden2low]

Well, I left the battery disconnected about an hour while I ran some earns. Now while I am letting it idle for 10 minutes or so then shut it off no codes but 111. But take it out for a drive and the engine light will come on for a few minutes then I stop to make a u turn, it goes out for a bit and then comes back on. Like it comes on when accelerating almost and then goes out when you are coasting or something. So the 02's that I had taken were still working as it was acting the same way before I put in new one. A couple of times it was hard to start before I started getting an engine light on. Now this was after driving the car as it was warmed up. So when I checked the codes, 02's popped up under fuel control, so I thought, ok replace the 02's. So in all I have replaced the 02's, a clean MAF and even cleaned out the IAC

 

[SHOYAY]

Still sounds like a bad O2 sensor or wiring. I had that problem with a taurus slo. Just because an O2 sensor is new, doesn't mean it's good lol. There is also a possibility that your converters are getting plugged.

 

[riden2low]

Yeah, the cats might be bad. The 95 just turn 117,000. I took off the throttle body and gave it a cleaning even tho it wasn't that bad but still nothing. Now that I have been taking things off and cleaning them, the idle seems to be screwed up. Some times the car won't even idle and dies until it gets warmed up and even then the idle is about 500 rpms.

 

[riden2low]

How would I check to see if the cats were bad? Tried the reset of the IAC but that didn't do much good. Now the thing is that the car starts up but won't idle unless my foot is on the pedal.

 

[riden2low]

Well, an update on this 95 ATX. I had extra IAC laying around and put that on the car yesterday. At first it ran fine but from my last post, the car wouldn't idle. So just reinstalled the old one and now the car runs but has little surge. So I am just going to replace the IAC with a new one. My shop manual states "do not clean" and on the site here most everyone cleans them. So that I hope will be one problem down. As for the 02's being bad even tho are new. I am going to replace them with a set that is in my 93 ATX and if they run fine in the 93 , hey I am good to go. Just start looking at somewhere else that is causing the engine light to come on at random.

 

[SHOYAY]

IAC does sound bad, ie the surging idle. You can check the cats with a back pressure gauge. You you it in the hole for the 02 sensors before the cats, if there is excessive backpressure, your cats are plugged. Also, I'd triple check all the wiring for the 02's. Follow them from the sensor to the harness.Also check your o2 connectors.There could be corrosion there,

 

[riden2low]

Update. Still the same codes. 173 177. I have 2 SHO's as stated earlier and I have taken the 02's off of one and switched them with the other. I know, a pain in the butt but at least I could see if the 02's were bad. Good as gold. They ran fine with no codes on the 93 ATX. Got the new IAC and put that on. Some what better in idle but once it warms up it will surge. Strange too, taking the 95 on a test drive, I noticed when you let up on the gas the the car will keep going at around 1500 rpms like the throttle is stuck. Yes, I a have taken the throttle body off and gave it a cleaning. In which it was pretty clean. Apply the brakes and the rpms will come down. Come to a complete stop and it will idle at about 800 rpms but if you sit long enough you can hear the engine and see on the tach that it will start to surge from 800 to 1000. Been reading a lot from the search on here and see something that might help, go out and try it come back with the same problem.........

 

[rubydist]

if you changed the iac, and if you did not perform the complete idle reset procedure, the engine will surge and idle stupid for about 2-3 days before the pcm learns how to control the engine speed with the new iac. during this time, you can expect to see the check engine light from time to time as the pcm is confused about controlling engine speed.

173 and 177 are codes that are saying the engine is running rich on both banks. in my experience, these codes are rarely from bad o2 sensors (generally, bad o2 sensors report the system as lean) so you are having some fuel or combustion issue.

if you are not experiencing any miss, then most likely you have one or more injectors that are not shutting off, causing the engine to run rich. run injector cleaner for a few tanks of gas, or (like I do) put around 5 oz of acetone per tank for a few tanks of gas.

if you are experiencing a miss, then diagnose that - plug, wires, coil, dis, etc. could be causing that - any of which could cause the rich condition.

btw, have you changed air filter lately?

 

[riden2low]

I did a KOER test and the code came up with 9 so I am fine there but I will do another test with the new IAC. Yep, somewhere there is something going on. The air filter looks good but when I drop in to pick up some injector cleaner I will get another air cleaner. This is the wifes car so how long it has been doing this who knows. I hardly drive it. The 93 atx is my car and it was in sad shape to start with and with all of the help that I get on here, the thing runs great now. I did do the reset for the idle and seemed to help but slowly started to have the same problems after test driving the car for about 30 miles. So I will keep hammering away at it.