Hi folks, have a 1982 V6 Camaro. Check Engine Light comes on while driving, used a paper clip to read computer code, "45", thought it was bad oxygen sensor so replaced it but problem still persists. Anyone have any idea how to correct whatever is causing the "45" code readout???? Thanks!

 

Here is a trouble tree you should follow.
http://www.chevythunder.com/o2_sensor_code_45.htm

 

I'm having the same problem right now with my 88 v6. Changed the maf, tps, idle air, plugs, coil, vacuum lines, fuel regulator, O2 (twice) and even the prom, AND ecm. The light comes and goes intermittently after it warms up, even though the car runs perfect and the plugs show to be burning perfectly, and do not appear rich at all... I'm lost as well. Following your post, maybe we can figure this out together. Yesterday, when I put a new maf on, the car ran even smoother ,but momentarily had a map sensor code 33 low vacuum.. which though not having a map sensor.. which is weird to get the code and not even have one, I do have a EGR vacuum switch which looks identical, which I played with and cleaned out, and the light appears to be gone now.. but besides that, I'm lost... The plugs burn perfectly, but when it throws that code 45, my fuel milage goes out the window to about 10 mpg..

 

I've seen where coolant temperature sensors and air temperature sensors will set a light on for an Oxygen sensor issue, but it sounds like until it happens, your cars are both running normally. Maybe check the readings of the coolant temp sensor when the light is on and see what you get? It could be causing the ECM to add or lean out the air. Just a possibility since JTD replaced all of the other sensors.

 

QUOTE

How do we check the reading of the coolant sensor and what does it need to be at? I did replace the air charge temp sensor as well, but have not done the coolant sensor yet. Anything he's trying I'm trying lol. Not trying to hijack his post.

 

 

Thanks to the folks who responded! The Garlitz Museum is only a few miles away, plus there is a place where they work on, and sell, antique and classic cars. I am thinking maybe if I can find a mechanic familiar with old cars, one not dependent on computer readouts, maybe they will know what to do about the "45" readout. Its a long shot, but I am not that technically savvy. I am wondering if anyone still uses the "SUN Engine Analyzers" from decades ago. Seems like today's mechanics only know how to do what the computer readouts tell them to do. Sad!

 

Well I haven't had any luck yet. Got called back out to work before I received the new temp sensor in, but did double check timing and fixed yet another vacuum leak before then, but still no luck. Maybe that temp sensor will make a difference. Also I found that the sensor on my evap cannisters is getting hot as hell, which is strange.. so looking into that as well. I've already changed all the parts that I would think logically would cause this.. now I'm kinda just parts swapping,and shooting in the dark.

 

Do you have any popping, or back firing in the exhaust during shifts or letting off the throttle? I do, even with a new cat and all the other crap I've done trying to figure this out.. I'm starting to think after reading and going back through threads from years ago,that it might be my deceleration valve, which is discontinued and I can't find anywhere. A faulty one allows unspent fuel out the exhaust... Which causes the back firing in the hot cat and exhaust.. and in my head it makes sense, that it would also cause the O2 to read rich, especially since between shifts, your foot is off the gas, throttlebody is closed, and less air in the motor means its less lean and more rich for that moment, and from what I read, it's purpose is to decelerate the drop of rpms between shifts ( this is in manual cars only by the way) to help allow a better rpm match when the clutch is released..stuck valves cause it to hold rpms longer than it should.. which mine does for sure, and seems to be intermittent, which is why I keep replacing vacuum lines because I always thought it was a vacuum leak causing it, and sometimes it has been.. I'm stuck in a hotel right now for work,and my phone should be ringing to take a train back in a few hrs, and will update you to let you know what I find when I disable it. hopefully this is it. I already am beginning to bald and this isn't helping it. Here's the thread.. skip to post 39 and start there

https://www.thirdgen.org/forums/v6/132456-two-quick-2-8-a.html

 

Mine is an automatic, car runs perfect, even when light comes on. Sometimes if I pull off the road and park the car for a minute then start it up, the light is gone and doesn't come back on for a while. The light coming on is hit and miss, that is what is so annoying, sometimes it goes on, then stays on until I pull up to a traffic light and the light goes out, sometimes not! Revving the engine doesn't get rid of it, however the light coming on seems to be more frequent as I drive the car more. Stumped!

 

Yeah, it's sounding like we have the same problem then so my issue is probably not the valve then like I had thought and hoped for. Mine runs and idles perfectly and smooth, with the exception of a little pop or slight backfire when shifting down occasionally and it seems like it stays reved a little longer than it should sometimes after startup or pulling up to a stop light when my clutch is in. And my light is intermittent and usually don't come in until the car is warm and then goes away after a little bit, and might pop back up eventually.. it also doesn't affect how it runs, with the exception of my gas milage goes down the drain dramatically it seems. Well crap.. hopefully we'll get this figured out before I say screw it and just pull the motor and overhaul it lol. Good luck