Check engine light “ low intake manifold pressure “

ItascaJoe · 07-15-2019, 06:54 AM

I’m on a trip from south Fl to Pittsburgh. As I’m driving through the mountains of WVA. About 400 miles from Pittsburgh, I get a check engine light. Every thing seems fine so I keep going to my destination. While driving I notice the check engine light goes off for a while then come back on, different intervals. The MIL light never goes out. I check the code and it says “ low intake manifold pressure”
Here is my question. I got the coach with 18000 mi I now have 38000 on her. I’ve never had the air filter checked and I’m not sure if the previous owner ever changed it. Could that be the problem also the air filter gauge is fine..
FTL 24/7 says could be bad sensor or a leak somewhere in the intake.
He also said it would be okay to drive home as it won’t de rate the engine.
My plan right now is to change out the air filter. Thanks

ItascaJoe · 07-15-2019, 06:55 AM

Opps sorry ISL 8.9 2014. Cummins.

ItascaJoe · 07-16-2019, 03:19 PM

I have an update. I replaced the air cleaner and took her over to Freightliner of New Stanton Pa. They plunged her in and decided that was the problem, all other components of this system were ok. The morel of this story is to not trust that air filter gauge with the yellow marker. Mine was filthy dirty as I thought it was okay by that gauge. I will be changing it by miles now.