1995 Bronco 4X4 3.58 L Engine

||Questions: || ||1. What is the EGR Valve Position (EVP) sensor? What does EGR stand for? Exhaust gas recirculation. Injects a small amount of exhaust gas into the intake stream to reduce NOX.

||What does the Electronic Valve Position sensor do?

Tells teh ECM whether the EGR valve is open or closed.

||2. If this EGR thingy is kaput would it cause rough idling/backfiring ||driving when engine is cold?

Yep. Causes a lean mixture.

||3. does the TAB do? (Thermactor Air Bypass solenoid)

Thermactor is the air injection pump. Air is pumped into the exhaust ports to encourage post-cylinder burning of excess hydrocarbons.

||4. Would the Engine Coolant Temperature sensor (ECT) cause rough ||idling/backfires driving when engine is cold?

Yes.

Texas Parts Guy

Thanks. And rats! Which one would you replace first?

On Sat, 03 Jul 2004 00:27:32 +0000, Zeitsev rearranged some electrons to form:

Rather than shotgunning it, why don't you pull the codes and let the computer tell you what's wrong ?

You do mean a 5.8 liter or 351 cubic inch engine right? I was unaware the Ford Put a 3.58 liter engine in any Broncos...

Oops. Yes, I meant 5.8L. Must've gotten a little trigger happy. I think it converts to 353.87 so thats close enough for the military. :o).