Do you have a scanner that can read data? Might wanna have a look at long, and short-term fuel trims.

 

I have a flashpaq that can do datalogging... I THINK, I'm not sure how to use it, my code scanner also might do something along these lines, I've never really looked into it cause I don't really know how to use those features.
When my scanner tries to do an O2 test it says it's not supported on this vehicle.

I think I may have to get into learning these features.

 

All learning is knowledge, and therefore Good.

Yeah, if you are gonna work on these fellers, need to get real comfy with the tools.

 

I haven't really done much at this point, replaced all 4 O2s now, but I'm not driving much lately.
I'm kind of wondering if I have leaks in both manifolds though....but like I said I don't really know what could be causing such a problem as both cats going bad, and my truck is getting 9 f%$#ing MPG

I'm not expecting a prius here obviously, but 9mpg just isn't right. I'm really hoping I can fix whatever I need to and get it up to hopefully 12mpg. I'd be so super happy with 12mpg lol.

 

What brand O2 sensors did you install?

 

NTK 23160 and NTK 23158


As soon as they become available in (hopefully) a few weeks, I'll be installing American Racing Headers long tubes to address the manifold leak(s) and likely doing a custom exhuast from the headers back.
Thinking duals with an H pipe, and pacesetter high flow cats. I already have the cats on order, and headers are awaiting the donor vehicle which should be dropped off today, by none other than 04 HEMI 04 himself

Aside from manifold leaks causing excess oxygen to be pulled into the system, what other things may cause such a loss of economy? I mean from the factory aren't these trucks rated at like 14mpg city? (you know, under absolute perfect conditions lol)

 

I think if you manage 12 around town, you are doing good. But, there are a LOT of variables in play there. Even WHERE you get gas makes a difference. Might try resetting the PCM, and let it re-learn your driving style.

 

ya, if I could hit 12 I'd be a happy camper man.

all our gas here now has ethanol in it now

 

Been that way for years around here. (decades??) There are still places that sell pure gasoline, but, the nearest one to me is 20 miles away. So, simply not worth the drive.

 

so I hooked up my flashpaq for datalogging, and it seems perfectly useless. As far as I can tell this model doesn't have anyway to store or maybe remove the logs from the tuner, and it only logs 4 things at a time.

so when I had it set to O2's the upstream (I think) were jumping around, but the downstream (I think) were both stuck at 99.21 (%?)

now I don't know what any of that means and I don't even remember what the stat was exactly.

so at this point I think I might just try and sell it.... not sure it's going to do me any good at this point.
I'm leaning towards maybe getting an HPTuners instead, or possibly SCT..... I don't know anything about SCT though and HPT seems like a good bet.