Hey everyone, I have searched the threads and found a few threads on fuel economy but nothing seemed to make a difference. I have a quad cab 2005 Dodge Ram 1500 Daytona edition 5.7 hemi. It has 4x4, CAI, aftermarket headers and exhaust ( No Cat) and 190,000KM as well as some sort of chip that the previous owner put on it, I don't know much about it. I have done plugs (16 champion copper), wires, TB cleaning, PCV and checked tire pressure all within 8000 KM as well as oil changes. I'm averaging 25L/100KM with a soft right foot. I have noticed when I fire the truck up that it does occasionally smell rich; possibly the lack of a Cat or the Oil consumption?. I have calculated the fuel mileage myself and the math is quite simple with the numbers I'm getting... 400KM to a 99L tank right to the gas light. I have two codes for P0420 and P0430 for the lack of the cat. I could care less about the CEL. I did throw the Anti-fouler on the two O2 sensors but the light is still on. I have read that the last two O2 sensors don't deal with the Fuel/air mixture? Is that correct? My next move was to clean out the EGR valve as I do have oil consumption. While taking the EGR valve off of our parts truck (Exact same truck, 05 Daytona ) I snapped the bolts off of the egr. So to say the least I'm quite scared to do that to my truck ahah. Any help is appreciated.

 

That converts to about 9.4 miles/gallon. For comparison, my 04 1500 QC 4x4 was getting about 13mpg city in a hilly environment. The computer controls the injectors and ignition timing. In general I would perform all typical engine maintenance and have a look at the vac/fuel trims/ timing advance values using a scanner. I'd pick two static points, like idle and 35 mph going up a light hill and see what is going on with those values. But since the previous owner changed the computer characteristics, they might have programmed it to run rich. I'd probably set the computer system back to stock and start there.

 

Your truck is a perfect storm of bad fuel economy. Between the nature of the beast (a V-8 pickup) and all the modifications, it's been tuned for power not economy. The chip and lack of a catalytic converter make it illegal in the U.S. I don't know about Canada. I'm assuming you don't have emissions testing in your neck of the woods. I don't have conversion charts handy but if everything is running right, you'll be lucky to get 12 mpg.

Before you risk snapping the bolts on your EGR valve, are you sure that's where the oil is going? You don't have any leaks? I'm wondering if the cat. removal was because it was oil fouled. 400,000 km is about 248,000 miles. It may be burning oil around the rings.

 

Okay that does make sense. Ill get it tuned back to stock by dodge and see where that takes me. My mechanics teacher does have a scanner tool so I'll give him a shout and see if we can work something out. Thank you.

 

We don't have emission tests down where I live. As for the oil consumption, I have not ran a compression test yet and the EGR valve was just a hunch as I heard the symptoms of one going bad being poor fuel economy, rough idle ect. Looking under the truck right under the drain plug there is a drip. I am certain it is not the drain plug because where the drive shaft connects to the (front diff?) seems to be wet and the way it lines up I could see a leak from that being whipped around by the drive shaft thus following the drain pan to the bolt. If I were able to get my hands on a smoke machine I guess that wouldn't hurt to check as well as a compression test. My Dads old truck ( 05 Daytona as well) had the exhaust on it as well as the CAI that we moved over onto my truck. I do know that its not made for fuel economy aha but his truck all the way up to 350000KM ran strong and the same if not better than myn power wise. With him driving the absolute life out of it he was able to 19L/100km that's why its kind of bothering me. Ill try to get these tests done next week and I'll let you guys know. Thank you.

 

Your mechanics TEACHER? I've got a Cadillac Escalade I bought from a guy training to be a mechanic. 1 1/2 years later, I think I've corrected what he worked on. He put a "system" in it and removed it when we swapped. I finally have the remnants fixed. He kept putting coolant in it when it was a $9 part that took me 15 minutes to change. I hope he followed a different career path.

Definitely get it back to stock. Unlike 50 years ago when I built my first car from a frame and suspension, you can't just bolt parts together and go.

 

I'm thinking that he is taking mechanics and he is talking about his teacher

Winter fuel and cold temps will also contribute to lower fuel economy. Longer warm up periods and the winter fuel can really hurt.

 

You could be right. I'm not immune to the occasional case of cranial flatulence. I answered another post where someone had a mechanic working on their vehicle and in my head I connected the two posts.

 

Yeah I am currently in mechanics class. I just took the truck into the dealer today to get it flashed back to stock. Ill let you guys know how the truck reacts in a few days. Thanks!

 

Good tuning will often improve your fuel mileage over a factory tune.