Considering purchase of 00' Sport with PO400 code & warn

[mckaymotoworks]

Vehicle has 166K, seller says the ECM is throwing PO400 EGR, as well as 4x4 light and anti-lock brake light being lit. He said a mechanic checked the usual suspects, found no issues, so seller replaced the EGR sensor himself which cleared the code for two days, but has since returned.

He listed on CL in another area because we have emissions here, asking $2400. What are some possible causes and what should I be looking for? Once the seller returns to town, I will check the vehicle out, perform a compression test etc.

[mtazido]

The solenoid,

I had this same issue, I check the solenoid resistance and it was fine, I applied 12volts and click!
So everything passed and I was baffled until I realized it was not closing off any flow.

When air is passing through the solenoid and you remove and replace power to it, I had nothing but a click sound. It was not working to turn on and off the flow of air (Exhaust gasses I mean)

So check it for 30 - 25ohms
Check it is actually doing what I is supposed to.

Not exactly cheap, so def test it.