Due to other codes, I have replaced the oxygen sensor, the fuel sensor, the EVP sensor and all vacuum lines have been rerun. I got the 334 code and under advisement from a mechanic friend, replaced the EGR valve. I am still getting this code. Maybe the EGR solenoid? Would appreciate some input?

 

This is for a '93 F250 5.8L engine code H

 

I would look at the sensor on top of the EGR valve. Usually that is the problem, or possibly carbon build up under the valve. It states the EVP voltage was too high. There is a pintle under the EVP that tells the computer how far the valve is open. We have taken the old one and filed a little off the bottom of the pintle to change the voltage output. Or add a piece of duct tape to the bottom of pintle. More than likely you can file the pintle off and change it to be in specs.

 

It means the EVP sensor that sit ontop of the egr valve is reading above about 0.65V. It should be much lower, around .050V. The easiest way around this is to put on a new egr valve, which is probably carboned up. Also, check for a code 332 (insufficent egr flow) on a KOER.

 

Thank you both for your responses. I have already put a new EGR vlave and the EVP sensor which sits on top of it. Based on what each of you has said, I will blow out the pipe the valve connects to and I will check the new sensor for proper working order. Yes, I had gotten that 332 code earlier and that is when I chankged out the sensor on top of the EGR valve.