Rough idle and gas smell - Express 3500

[devhill]

Hello everyone

I just got a Chevy Express 2003 3500 6.0. It was sitting for a long time and i got it in exhange for a job. I did an oil and fluid change, drained the old gas, installed new spark plugs. It turns on perfectly, and it drives smooth. The engine sounds really good too, it only has 125k miles. But when its on idle the engine misfires a little bit and there’s a smell of gas and a little bit of black smoke. The scanner says its the EGR Valve and i was going to replace it but to my surprise, the connector its not there. I looked everywhere, and i just can’t find it. My question is, are these sympthoms related to the EGR Valve or could it be something else? And if so, should i get a new harness or there’s another way to wire the connector?

[MountainManJoe]

Hello everyone

Welcome to the forum

I just got a Chevy Express 2003 3500 6.0.

You posted in the Astro / Safari section. Moving your topic to Chevy Express ...

there’s a smell of gas and a little bit of black smoke.

running rich then

The scanner says its the EGR Valve

Scanners are usually more specific than that. What was the exact code number and definition?

[devhill]

The code is P0405 - Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Voltage.



Here’s a picture of the EGR valve but the connector is nowhere to be found, a mechanic is coming to check it out tomorrow, he said he can wire it from the PCM, i just hope it fixes the problem. That’s the only code i’m getting.

[MountainManJoe]

My question is, are these sympthoms related to the EGR Valve

Yes they very well could be since EGR affects the combustion mixture. Start with fixing the EGR system and see if the symptoms go away.

Here's how the EGR valve should be connected (#5)

[devhill]

So the auto electrician came and he couldn’t find the connection either and he couldn’t get it from the ecu.. Told me to try to get a new harness but i’m having trouble finding the right one. Do you know which one could be since the 6.0 its a little different from the other ones?

[MountainManJoe]

boneyard is probably your best bet

[devhill]

I didnt have any luck at the junk yard. I found this one on ebay
https://www.ebay.com/itm/326035101112?m ... media=COPY

I was reading that its the same one for the 4.8 and the 6.0 savana and express. But i just want to be sure lol