Hi guys i have a 1988 camaro tpi 305 my engine light keeps coming on code 13 02 sensor i put a new one reset the computer code came back on again so i took the o2 sensor back and got a new one put that one in and reset the computer took it down the road light came back on again some one said it might be the tan wire from the computer is not ground out i can't find it any help will be nice

 

The O2 sensor ground is on one of the grounds at the back of the cylinder heads. There is a stud at the back of each head with a bundle of ground wires. Check all of them.

GD

 

Excellent suggestion. Ground is part of the circuit, and if it's not "connected", then all sorts of weird things can happen.

Keep in mind at all times however, that when the computer puts up a "code", it doesn't ALWAYS mean, "the such-and-such is bad". Rather, it often means that it's receiving inputs from several sensors that can't possibly all exist simultaneously. Like, the TPS (throttle position) says it's wide open; the MAP (vacuum) says it's at idle vacuum; and the RPMs are low, let's say 700 or something. Those 3 things CANNOT POSSIBLY occur at the same time in the same engine in the real world. (well, not in my universe anyway...) NO WAY you can have the throttle wide open, the engine at idle speed, and high vacuum, at the same time. When confronted with such conflicting inputs, the ECM sends you a "code", which is its only way of saying "I'm confused and don't know what to do, here's the most likely thing wrong I'm programmed to tell you to check".

However all that may be, the O2 sensor is simpler. Usually when you get one of those codes it means that (a) the sensor is bad in some way or disconnected, or the wire is shorted to ground somehow, like melted; (b) its shell isn't grounded, which could be because the ground wires are fornicated, or merely because the manifold itself isn't grounded; or (c) that the ECM is getting something from the sensor, but when it tries to adjust the fuel by changing the injector duty cycle, nothing happens.

I can't recall whether 13 is "O2 sensor rich" or "O2 sensor lean". Obviously besides swapping O2 sensors endlessly, at some point you may need to figure out why the ECM would be telling you that. For example a typical cause of "O2 sensor lean" codes is, one cyl isn't firing, which dumps VAST amounts of oxygen into the exhaust NO MATTER WHAT ELSE is going on. Reason being, it's an O2 sensor; not a mixture sensor; not a lean/rich sensor; not a fuel sensor; the only thing that it is, is an O2 sensor. It detects the presence of OXYGEN, nothing else, PERIOD. Meaning, if there's O2 in the exhaust stream, it'll see it, and it'll try to add fuel at certain times (maybe all times) to make up for the perceived "lean" condition, but if it can't do that, specifically if a cyl isn't firing, it won't matter in the slightest HOW MUCH fuel it dumps in, it'll STILL see abuncha O2 in the exhaust, and then since it can't control it, it'll set the O2 code. Not, the way more modern computers can, "cyl 7 misfire" or whatever. With the old Ice Age computers these cars have, you can have stinky burn-your-eyes black-smoke rich idle, and a "O2 sensor lean" code at the same time, if you have ignition-related misfires.

So, the first thing you might want to try is, put in new spark plugs. Not "check"; not "clean"; not "they're only x,xxx miles old"; not, "they were new last month"; PUT IN NEW ONES.

 

thanks guys i did put in new spark plugs wires and cap and rotor i check the ground wires on the driver side behind the head i was geting a grounds there funny thing is this happen afther i tune it up the car runs like crap at high speeds i geting a gas smell when i shut it off like it runing rich

 

So, is 13 the "rich" code, or the "lean" one? or just, a "not working" one? (can't remember, my old-timer's disease is acting up again today) Correct course of action may vary considerably accordingly.

 

yes she is running rich and the light go on and off when i can going to hook up a wire to back of the head to a ground and see what happens right know trying to find out why at 70 my rpms are at 5000

 

Didn't ask that. What I asked was,



They're not. Unless you're in 1st gear or something. Rather, your tach is wack, like everybody else's.

 

There is a tan ground wire going from the ecu (next to a pink wire if I remember correctly) to the back of passenger side head that is impossible to reach. Mine was corroded so I made a new ground under the dash. No more code 13. That code says the ecu gets no signal from o2 at all.

 

Bringing this one back to life@ Gomez83 you corrected this by grounding the tan wire from ecm harness to the car?

 

D6 of the 1227165 86-89 tpi ecm is O2 ground if that’s what’s in your 88 profile.

 

@ tuned performance no it's for a 91 Z28 still a tan wire?

 

E15 1227730 ecm on the yellow or green ecm connector .

 

Are the connectors labeled how will I find e15 is there a color?

 

It’s labeled small but labeled

 

@ tuned performance is it common for them to lose ground?

 

No, is the circuit showing open or just stays at .450mv or consistently is lean lower than .450 mv in closed loop?

 

Car will not go in the closed loop

 

Cts reading properly ? O2 just stays at .450mv ?

 

Not on the single wire sensors.... they ground through the sensor body through the exhaust manifold.

The wire for O2 sensor ground at the ECM is just a reference for the ECM. I believe that wire just ties into the main ground.

 

@ tuned performance O2 is new Ac Delco as well as the CTS and ECM I'd have to put my scanner back on it but I unplugged coolant temp sender on the left side head and it runs better

 

The left temperature sender is for dash gauge . Cts yellow and black wire front of the intake.
just curious have you ohmed the injectors cold and hot ? Wound tell flow but state of coils.

 

@ tuned performance injectors are new from south Bay as well as the regulator and fuel pump and sender

 

Is this a new problem or old trying to fix with recent injectors D3 injectors?

 

@ tuned performance this is a new issue after injectors they are the ford crown Vic style

 

Datalogging to see fuel trims, infared temp gun pointed at each exhaust port to see if a single cylinder is lean especially on drivers side to try to diagnose the issue. Those injectors seem good could of got a bad one not flowing well. Pull plugs to read . Or just try a afpr to get fuel trims into range. Or could be a vacuum leak.

 

Yes. Located the wire at the ecu and grounded it at a new chassie location. Code gone.