Bad MPG. Is cat clogged?

[Dirtman]

Didn't they ditch the fuel pressure regulator in 1998 when switching to the returnless fuel system...

 

[Uncle Gump]

I'm not exactly sure when they went returnless... but if there is no regulator on the rail... it is a returnless fuel system.

At 12MPG... something just doesn't seem right. No codes... no drivability issue... no fuel leaks...

 

[Eddo Rogue]

clogged cat will smell like rotten eggs.

 

[Pauls14]

I'm not exactly sure when they went returnless... but if there is no regulator on the rail... it is a returnless fuel system.

At 12MPG... something just doesn't seem right. No codes... no drivability issue... no fuel leaks...

I guess at the moment, I should check fuel and exhaust (cat and O2)
About plugs, coils, wires I don’t know. Engine works smooth, start good.

 

[Pauls14]

clogged cat will smell like rotten eggs.

Something smells after ride (around engine and exhaust (between cab and bed).

guys what do you think about EGR?

 

[Roert42]

I believe you would get a code if the egr was stuck. Although I don’t know that it would effect fuel economy anyway.

 

[adsm08]

Something smells after ride (around engine and exhaust (between cab and bed).

guys what do you think about EGR?

A little bit of EGR flow at idle will make it run rough. A little bit of stuck EGR valve will make it not start too.

 

[Pauls14]

A little bit of EGR flow at idle will make it run rough. A little bit of stuck EGR valve will make it not start too.

Mine engine works smooth. Ok, thank you

 

[Pauls14]

Hi guys. Finally checked fuel pressure. On idle around 50-65 (was different pressure each time). But when I turn off, pressure down until 20 (during 15 minutes). Is it bad?

 

[Dirtman]

No. Yes.

The pressure should hold for a pretty long time (like weeks).

BUT essentially every fuel pressure guage I've ever owned or used leaked just enough to make checking that impossible. So I'd be inclined to blame the guage for the pressure drop before blaming the truck...

If it's not the guage you could have a leaking injector, or leaking check valve in the pump.

 

[Pauls14]

No. Yes.

The pressure should hold for a pretty long time (like weeks).

BUT essentially every fuel pressure guage I've ever owned or used leaked just enough to make checking that impossible so I'd be inclined to blame the guage for the pressure drop before blaming the truck...

Maybe gauge from Harbor Freight is crap)

 

[gw33gp]

clogged cat will smell like rotten eggs.

That is not always true. A bad cat can smell like rotten eggs but a clogged cat will have little flow but may not have much smell to it. My main cat clog last year due to one of the front cats breaking up and all the material ended up in my main cat. There was no smell but there was no power because of the restricted exhaust. It would start up and idle normally, but as soon as I tried to rev it or drive, it would bog down.