Low power

[PlayingWithTBI]

I would guess the tire's about 10% bigger than stock (check me on this) so the indicated speed is correspondingly about 10% lower than actual.

It sounds backwards, using these numbers, a bigger tire would read 22 MPH while actually going 25. Maybe a gear change happened too?

 

[PlayingWithTBI]

speedo is about 3-4 mph fast (if it says I'm going 25 I'm going ~22)

As said here.

 

[1998_K1500_Sub]

It sounds backwards, using these numbers, a bigger tire would read 22 MPH while actually going 25. Maybe a gear change happened too?

Good catch... and I actually gave that some thought when I read it and it seemed to jibe. Silly me.

I wonder what the actual story is here.

 

[PlayingWithTBI]

Good catch... and I actually gave that some thought when I read it. Silly me.

You were right, OP's was backwards, I just quoted you instead of him.

 

[Purplestaff]

It sounds backwards, using these numbers, a bigger tire would read 22 MPH while actually going 25. Maybe a gear change happened too?

Or the gauge could just be off, it is a Chevy gauge

 

[Purplestaff]

Or the gauge could just be off, it is a Chevy gauge

My gas gauge is way off and temp doesn't even work. Lol

 

[Purplestaff]

I should add, I get terrible gas mileage, like a quarter tank a day, and I drive 30 miles or less in a day. I know the O2 sensor can cause that as well as a lack of power

 

[PlayingWithTBI]

I should add, I get terrible gas mileage, like a quarter tank a day, and I drive 30 miles or less in a day. I know the O2 sensor can cause that as well as a lack of power

Yes it can, and if it's bad your trouble codes should show it.

 

[1998_K1500_Sub]

I should add, I get terrible gas mileage, like a quarter tank a day, and I drive 30 miles or less in a day. I know the O2 sensor can cause that as well as a lack of power

Well the OBDI ECUs don't have the rich set of codes and diagnostics that OBDII has, but there's still much useful information to be gained.

Find someone who can help you out. A good tool can not only read the codes but show sensor information (O2 sensor, TPS, MAP, coolant temp, etc.) all of which will go a long way to sanity-checking the health of the engine and its control system.

 

[GMCTruck]

Plugged up air filters and fuel filters will cause noticeable loss of power.