mjb

I'm hoping some folks in the know can help with this. I just put 2 new 502 long blocks in my boat. I reused the old manifolds and throttle bodies. The engines seem to run well however when I hook up my scan tool, it gives me a fault code for bad MAT sensors and it shows 0* MAT on BOTH engines . I did clear the old codes first. Seems unlikely that both engines would have bad sensors???
1) Do these sensors frequently go bad?
2) How would a non working MAT sensor effect engine operation ?
3) Will it hurt anything to run the boat for a weekend or two until I can get new ones?
THANKS- MJB

Dave_N

Forgive me for asking, but you did hook them up, right? The Manifold Air Temp (MAT) sensor is on the underside of the plenum on the starboard side of the engine. It's easy to miss.

I don't hear about too many failures of the MAT sensor. Two at once is very unlikely - but is possible I guess.

Dave

mjb

I'm pretty sure that I did hook them up right but I will check tonight. I also thought it was odd that both would go bad.
If they did go bad, will it hurt the engines to run the boat until I can get them replaced??
Thanks- MJB

Dave_N

Before you replace the sensors, go through this procedure to see what the problem is.

Dave

mjb

Thank you Dave- It's really great that you take the time to help those who need it on this board. I'll check into this over the weekend. I hope I can solve it without having to bug you again.
Thanks- MJB