I own a 1998 1500 ram 4x4 with a 318. The truck gets around 7 miles to the gallon in town driving. I gave it an oil change and smelled a strong aroma of gas, so I checked all the plugs, wires, and distributer. I ended up replacing these do to the fact they were in terrible shape. Amazingly this had no affect on how it ran. I have replaced the cat and muffler (do to the fact that the cat was rattling), this also had no affect on how it ran, it just sounded better. I took it in today to have it looked at again and the so called mechanic informed me that my cat was running way to hot and the fuel was to rich. Of course he had no idea why it was doing this. I am hoping that someone would be able to give me an idea on what to check. Since this is my first Dodge truck, I don’t know what kind of power these trucks are supposed to have; I just know that a 4 cylinder pinto would probably smoke me.


All that has been done on the truck so far: Plugs, wires, distributer, fuel pump, k&n filter, all new exhaust from headers back.
The Rookie

 

Did you replace the O2 sensors when you did the exhaust? Have you checked the plenum for a blown gasket? How about the TPS,IAC,CPS? I would pull the throttle body, check inside the plenum for leakage. Clean or replace the TPS and IAC.

 

I would say replace the o2 sensor before the cat....wouldnt hurt to change the one after too.... I believe these control the fuel/air mixture and make sure it doesnt have one of those ebay resister mods that trick the computer into thinking the motor is always cold that might mess it up too although I'm not sure. you may have a blown plenum too ....very common you can look down the throttle body and see if it looks oily downthere and sometimes tell other signs are burning a lot of oil.

 

aghh Twisted you beat me to it lol!

 

1. You don't have to look down into the manifold. If it says Dodge on the side, the model year is 1994-2002, it has the 3.6L V6, 5.2L V8 or 5.9L V8, and the plenum plate and gasket haven't been replaced yet, its leaking. Fix it. Another option, if you have gobs of money, is to invest in a Hughes FI intake manifold.
2. Search here on the forums for "death flash". It was Dodge's solution to the plenum gasket issue. After the plenum issue is fixed, "fix" the "death flash" with either a Superchips tuner or a SCT. Hemifever is a good user to ask for the SCT, excellent customer service.
3. Replace the pre-cat oxygen sensor. As others have stated, this may be a good chunk of the problem. The thing is, if you don't also fix the plenum, all that burned oil is just going to coat and ruin the next sensor you put in. Same with that new catalytic converter, the burned oil will ruin it to if you don't get the plenum issue dealt with.
4. After those are done, look at the IAC, TPS, and MAP sensors. All easy to get at, all easily replaceable.

 

+1 jasonw ,,,, you should put that sum were, like take the insert key on your keyboad every time theres a bad mpg thread just hit the insert key a it there

 

LOL dodgeram07. I should. Thanks for the idea, think I'll actually do that right now...

 

Yeah.... Well the hes not the original owner so he may not know whats been done (neither do I or more than half of the posters here) to our trucks

 

If its not darn near completely spotless inside that intake, its leaking. Most owners don't care enough to fix the issue, from what I've seen. Some even pay just to have the gasket replaced, only to have it go out again soon after.

 

heck
the only thing i know about my truck before i got my greasy hands on it, it had an oil change every 3000
and had the **** driven out of it as a farm rig