A few days ago my CEL came on on figured it’s was the nuisance code for “catalyst under threshold “ that I always get because of the Miltek header and when I pulled it up I was surprised to see it was something different. PO172 for bank 1 rich, that it was a fluke since the car has been running great so cleared it and went on about my business.

Next day came back on for the same 172 but now my mileage has gone from 25.5 down to 11.9 in a 30 mile trek. I had to order a fuel pressure gauge today so right now I don’t know what it is or if it will drop so is there a common issue when this happens? I’m thinking the FPR is stuck open maybe?? The reason behind this is a few weeks ago I was running the car hard on the highway then lost power so had to cripple it home and found the vacuum line came off the intake that feeds the FPR. After putting it back on I was surprised to see how loose it fit so I zip tied it to the nipple and man what a difference in performance so it had been leaking for who knows how long with vac and now with full vac on the regulator it just gave out??

Any thoughts?

 

No ideas anybody??

 

Without vacuum FPR is closed,so you have max pressure on fuel line.FPR may have remained open after connection on vacuum line and you don't have enough fuel pressure for injectors.Check pressure on fuel line.Just my opinion.

 

I would guess a fuel injector could possibly be stuck open too.