So here's the situation. I just put a new EGR tube on my 94. The check engine light had been on for a while because I was runnin without EGR for a bit. Not very far though, too hard on gas. So I got around to puttin a new tube on today and disconnected the battery to reset the compy. Now here's what happened. I was drivin along, got about 5-7 miles and the check engine light came back on. Before, this would happen within 2 miles. So I hooked it up to a friends scanner, and we were told code 172 and 334 were comin up. But we don't have a way to tell what these mean. So I am asking all the wise beyond your years people here (cause I know there are a lot of us ) if anyone knows what these two codes mean? I'm gonna call the Ford dealer here to find out, but figured I'd give everyone here a shot first.

Trevor

 

172 = HEGO (H2OS) sensor fault lean. KOER or a CM code.

334 = EGR closed valve voltage high, KOEO, KOER, or a CM code.

You don't indicate the type of codes you got (KOEO for example), but you need to fix them in the sequence KOEO, KOER, and CM. You also need to fix then in the sequence of increasing numeric value (ie, 172 before 334 if for example both codes are KOER). The first noted sequence is where you begin.

 

There both the same, so they must be a KOER code. I'm pretty sure they weren't CM. I'll ask tomorrow. So what do these mean, and what might I have to do to fix them? Also, what do the different types of code mean (KOEO, KOER, CM)

Trevor

 

Thread moved to 87-96 F-Series trucks forum.

-Matt

 

KOEO = Key On Engine Off
CM = Continuous Memory
KOER = Key On Engine Running

334 is the EVP voltage being to high. Either you're EGR valve sticks, EVP is bad, or the wiring is bad. 172 could be caused by 334...ie, the EGR stays open and lets excess exhaust back into intake.