Finally got my car to run well...thanks to all with the help in the past. Everything is running well...all except a code 13,and I can't shake it!
It's an 89' Iroc/305TPI with only 1 mod,a Flowmaster 3" converter,muffler,and system. I have replaced this sensor twice and don't understand why when I clear the computer memory the code comes back. Both sensors check out fine,but this leads me to wonder if the exhaust system is causing this,or if it is a matter of the wire getting crimped when installing it with the o2 socket. I don't see any gas mileage side affects,the car is in the 20mpg range which I'm happy with. The last thing I want to do is get an expensive heated unit and find out the damn code is back.

Any ideas on this,anyone else had this problem?

 

Its a guess, but how is your fuel pressure?

I troubleshoot a "suspect" O2 sensor once. After swapping it twice I found out my FPR was bad, causing me to get an O2 sensor fault. The fault really meant that the sensor was not getting fluctuating readings because too much fuel was being dumped into the cylinders.

You might have the same problem, but may be suffering from lack of fuel.

Hope this helps.

 

I'll look into the fuel pressure regulator. It may be a little rich right now,but I'm not sure how the two are linked. The o2 is read by the ecm,which is looking at it's temperature...or is this wrong?

Niko

 

code 13- an alternate cause may be a sticking or misadjusted throttle position sensor, check the connectors from the O2 sensors and listen to that other guy

 

One other thing I have noticed,I can hear a ticking/tapping sound from the engine. Could this possibly be an exhaust leak which would affect the o2?

Niko

 

There are two leads from the ECM that it needs for the O2 circuit. "D7" is a single lead from the ECM to the O2 sensor (check that for continuity) and "D6" is for the O2 Sensor Ground from the ECM.

Try running a wire from the ECM harness on D7 to the O2 sensor to ensure that there is not breaks or shorts from the O2 sensor to the ECM and run D6 to a ground to ensure that circuit is not broken or shorted.

 

Yeah, I agree, check the O2 sensor wiring for breaks/shorts and make sure its ground path is in tact!!!!

Also, a weird exhaust leak can actually allow air to be sucked IN to the exhaust, causing a lean condition, but unlikely. but, I suspect a simple wiring/sensor problem.

Make sure you did not ovetighten the O2 sensor, too. than can cause false readings and a short internally if you crank it hard enough!

 

Thanks for the replies,the fpr checks out and the car is running pretty much dead on 6 degrees and 450 at idle. I torque pretty much everything to spec and did use my torque wrench on the sensor. The light tapping at idle does not increase with rpm,or at least I don't think so,the 3" system is loud and drowns out the engine noise. I think I'll look into the tap,thinking it may in fact be an exhaust leak and a possible cause for the code. Does this sound possible to anyone?

I'll post results for anyone interested,
Niko

 

That is not "normal". Your idle (in gear) should be 600 rpm and 700 in park. Sounds like you are in "Safe Mode" due to the SES code.

I am more inclined to feel Code 13 is a "circuit problem" between the O2 sensor, the ECM and Ground. An exhaust leak WILL cause eratic behaviour with the O2 sensor, I've experienced that myself. But it made it register lean and threw a Code 44 - O2 Lean.

But go for the easy fix first, but do run a "couple of wires" between the ECM, O2 sensor and Ground.

 

I'll also assume that you checked your timing at idle with the bypass disconnected.

 

I did check the timing at idle and it is at 6 degrees with the est disconnected. As I look at he tach at idle,it is around 550-600 and 750 in park. I'll check the o2 wiring and whole circuit in the morning,this o2 situation is absurd! I might be in safe mode,but I have no performance indications at all. I wish I had a scan tool,might be time to invest in one.

Niko-

 

I have continuity between the ecm and sensor,does anyone think the tapping sound is and indication of an exhaust leak and contributing to the o2 code? I can't visually see any leaks,and my impression is a leak would have to be a decent size to make a tapping sound. I'm just out of ideas,I hate taking the car to the shop.

Niko