Does anyone have a link to the codes? My 87 failed its emissions test and the Service Engine Soon light keeps coming on. The coolant temp never gets above 75 C. I used the paperclip trick and got two codes. The first was a 12 and then a 4. Any suggestions?????

 

Re-pull the codes - I don't believe a code 4 exists...

 

Yep, you need to do it again...no code 4. But if it's a 44, and failed emmissions that would make sense, that's an 02 sensor or problem with the 02 sensor circuit..most likely a bad 02 sensor, you have 1 on the drivers side....but re-pull the codes to be sure.

 

No code 4, lowest is 12.

 

Thanks for the help, I just tried again and I got 12 again (flash, pause, flash, flash). It did that 3 times then flashed 4 times in a row then paused then four more so I guess that would be 44? Would this be the reason its never reaching proper temperature?

 

I don't think the 02 is keeping you from reaching operating temps...but the engine does have to reach operating temps before it can go into closed loop.

 

so would it make sense for me to replace the O2 sensor or is there something else that is keeping the temp too low? I didn't get any codes that indicated a problem with the cooling system but the engine will not get to the proper temperature. The car seems to be running rich and I wonder if this is because of the O2 sensor or something else?

 

How many miles on the car? O2 sensors do get old and fail after a while.

How are you getting the 75 C temp reading?

 

The Code 44 is Lean Exhaust. First I would remove the O2 sensor and do a visual check for silicon contaminant (whitish). You can also volt check it with a voltmeter and also do a visual check on the circuit (maybe grounded my exhaust pipes), or misconnected. Normal is about .35v to .55v. The O2 sensor will give as low as .10v if the exhaust is lean. This sends volts to the ECM and the ECM tries to compensate by adding more fuel than needed and cause a drivability problem. Have you ever replaced the O2 sensor? I think they are about $25. You can also use the Field Service Mode to confirm lean exhaust. Start the engine and use the paperclip as you did to check codes. The SES light will start flashing. If off more than on...lean exhaust. If on more than off...rich exhaust. The SES light should blink one time per second for normal exhaust mixture. If you do all this and are sure its a bad O2 sensor...replace. Or you can skip all this, replace and cross your fingers. As for the engine temp that could be a open thermostat. That one is just a guess.

 

The car has 111700 km (69000 miles) on it. It has been in the family since day one and I've looked through all the invoices and the O2 sensor has never been touched. It looks like they only cost about $25 so I want to try replacing it and hope that helps. Any suggestions as to what else might cause my problems? Is it easy to change the O2 sensor? The service manual only says that it is difficult to remove below 125F.

 

Since you have the code, this needs to be checked or replaced. Yes it is very easy to change. I ran my vette on ramps, the O2 sensor is on the driverside just behind the precat. It is fairly easy to remove cold and the new one should have antiseize on it already. Remove the connector and use a wrench to remove. Intall in reverse (make sure its tight) and the sensor will smoke the first couple of minutes (antiseize). If this fixes the drivability problem get back if the temp problem still exist, which I think it will.

 

It's usually easy to get out, try removing it with the engine cold..if replacing it it what you intend to do. Could be an open thermostat preventing it from getting up to operating temps.

 

My 86 manual does not show a code 44

 

Never been able to remove an O2 (easily) on any engine cold - I'd try it warm.

44 means that it's sensing a severe lean condition and it's probably running on backup to keep it from stalling. Any air that gets into the plenum or combustion chamber that isn't measured by the MAF will make it run lean. If replacing it doesn't solve the code, you'll need to look for air leaks. And since it's enough air to trip the code, I'd start by clamping off the air hoses to the headers. A broken check valve or malfunctioning air pump system will deliver enough air to set up this condition. If that makes the code go away, you'll need to troubleshoot that part of the system.

When the ECM senses a lean condition, it adds fuel. If the measured (MAF) air isn't there to match it, the car will run rich and can easily fail emissions.

With the code, it should be running on backup and that will have the main fan running at all times. If the thermostat is working, it should eventually reach the threshold of the thermostat, but it may not stay there for very long. Once you get the code fixed, make sure the fan turns off. Otherwise, a scan will show what is being sensed by the Engine Coolant Temp Sensor. When it reaches 226 degrees, the ECM should ground the main fan relay and the fan should run for a minimum of 60 seconds. Make sure the a/c is off. With a/c operation, the fan will come on at a much lower temp, but your emissions testing is with the a/c off.

 

Mine came out easy cold, and I'd try that first before screwing around with a warm/hot exhaust.

Agent86, in my FSM 87 on 6E3-A-54 Driveability and Emissions-Fuel Injection (Poet) is where Code 44 was found

 

DOOOH, I didn't actually look in my book, i looked at my website where i store code info and it wasn't there. For some reason code 44 and 45 didn't make it there, but they are now
http://members.shaw.ca/corvette86/Code%2044.pdf

 

from the friendly giant!

 

 

I had a code 44 not long ago on my 91 . With the help from every-one on here I got it figured out . It ended up being my Injectors ( had to OHM them to find out ) and my Cat's were plugged and rattling and had to be replaced ( I think there issues we're cause from the injectors ) .

Here's a link to my thread about it

http://forums.corvetteforum.com/show....php?t=1352434


I hope this helps your code 44 and the info / help you get on this site is great .

 

If it is the 02 sensor, replace only with Denso or AC/Delco/Delphi. Don't go with the cheapie $25 Bosch from Autozone. They are often not calibrated to work properly with your ECM and can cause future engine performance problems and trouble codes.

Get them from these guys. They have free shipping over $50, too!

http://www.buyautoparts.com/gm-parts/