Mine as well, even though we don't do ethanol up here. I just assumed change in weather and gas additives due to winter. Now here is something I've been thinking about that is kind of along these lines....

What is the optimum temp for the engine to run most efficiently? (3.4L) If it runs too cool does it dump extra fuel in to try to get the temp up? My ScanGauge reads water temp is 188* - 197* most of the time. If I sit idel for some time, it will get up over 202 (215 highest). Now last summer, I would be driving and it would be 197 - 204* on average.

I hope I'm not hyjacking the thead, just looking for other options for the drop in milage...

 

i almost forgot, i did a little search about 3.4 valve covers, it's pretty common the valve cover bolt got loose over time. all the bolts on my were loose, finger tight, i got about 2mpg gain after tighten them up. try to use a small 10mm flex head ratcheting wrench. the passenger side was easy and the driver side was PITA, i could only reach 5 of them. i'm planning on change the valve cover gaskets for good very soon.

 

About O2 sensors: if they're out of spec, must they be replaced or can they be refurbished? If so, how? My search terms didn't bring anything up...

 

188 moving around 70 deg. 202-204 max on really hot day drops down to 190 from fans. possible to see 214 but it should never ever go above that, or even stay there for long

 

My scan gauge reads pretty consistantly between 189F and 193F, but they weather has been unseasonalbly cold. It's April and were still getting snow flurrys.

 

Getting 20% over EPA ratings is pretty far fetched.

 

Thanks! That gives me a good idea where to set my electric fans. I should turn them down a tad so they come on around 200 - 205.

 

That's right where I'm sitting as well.

We just got snow again last night. It tries to melt for a few days and then snows an inch or two.... And they talk about global warming!!!! LOL

Holy Cow!!! Orting Wa (nice little town).... Been there a few times. I loved taking my girls on the trails along the river there. I spent a few years in Puyallup while I was working in Redmond. Man I hated it!!!! LOL

 

The trail is great and it's growing, it now extends from Puyallup to South Praire. It also makes a nice volcano escape route for my motorcycle...
When Mt Rainier decides Mt Redoubt is stilling it's thunder, I'll be ready... or I'll be buried under 30ft of mud.

 

I've run into this too. I was getting 280-300 to a tank in town. I'm not good if I can get close to 300 on the highway or about 240-50 in town. Of course it sat most of this last year. I got back from Iraq a few weeks ago and my ex put only a couple of hundred miles on it while I was gone.

It's got synthetic in the transfer case, tranny, and rear diff. I haven't done the front because I haven't had time to pull the skid plate. I've planned on doing the plugs, have them in the garage. I need to pull my TRD filter amd clean it. Probably need to clean the TB and MAF. We'll see where that gets me.

I'm also glad that people are ignoring the MPG stuff. This argument goes on all the time and it's nice to see that it's being ignored on a thread that's about how to restore it and not how impossible that mileage is.