5.0 Smog Removal Aftermath

[lutter94]

I have done some searching and haven't found exactly what I was looking for.

Anyways, here is the problem.

I removed the cats and smog pump about a year ago. It has ran fine. Within the last month or two (it doesn't get drove much in the winter), a check engine light has been coming on when I am driving. It is not on when I restart, but will come on after a bit. KOEO has no codes. KOER results in DTC 311 and DTC 314.

DTC 311 - Thermactor Air System/Fault during engine run self test

DTC 314 - Thermactor Air System/Fault during engine run self test - Left Side

I have read that I shouldn't worry about these codes, since the smog pump is gone. But could the code have been active all along without throwing the check engine light?

I am slightly skeptical that the light may be coming on due to a O2 sensor. Since after installing long tubes, the right side sensor is in an unhappy position against the trans pan. And I would not be surprised if it was starting to fail. Another reason for me to think this is fuel mpg. I drove it 60 miles yesterday, and it seemed like it was burning more gas than normal. I haven't filled it up at the pumps yet. So I can't say for sure. I took it to town to drop it off to get gears installed. I don't have the time to deal with it, and the labor is reasonable......

Let me know what you think. Could it be a possible vacuum leak? At the end of the KOER test, the engine stumbles for a second, almost dying. I assume it is the EGR being tested, which seems like it is working correctly.

 

[rz5.0]

Did you cap off you vac lines... I wount worry about the codes but I though smog did not give a CEL..

 

[lutter94]

I plugged them. I want to check them once I get it back from the shop. I read somewhere that there are smog solenoids in the pass fenderwell that the vacuum lines run to. If so, they are still there and plugged in. Maybe I should remove those.

I didn't think it should throw a CEL either, since I had been driving it a year without a light ever showing up.

 

[94RedGt]

When i removed the smog system i took off all the vacuum lines related to the smog system, soon after i got a cel so i reconnected only the vacuum line that goes from the intake to the little selenoid inside the fenderwell and from the selenoid to the EGR valve, leave those connected or you will get a cel . The other codes you got are normal if u removed the smog system and they do not turn on the CEL. U can probably test your O2 sensors with a multimeter, do a google search on how to do it. With a digital meter u should see the voltage increase and decrease smoothly almost as it if was making a wave, if one of the sensors have an erratic wave then they are probably bad or one of the cylinder banks is running lean or rich wich is vacuum leak possibly.

 

[Slykin]

Did you remove your EGR valve? I did about a month ago and it started throwing a CEL. If that's the problem you can pull the EGR apart(three screws where it plugs in) and you'll see a little metal plunger. Just secure that down halfway and plug that piece of the EGR back in, and the light will stop. Or did for me at least.

 

[rz5.0]

Why would you delete the egr and still keep it on.. Defeats the only good thing of deleting it... but you are right. Egr will give a c.e.l.. Smog should not..