MPG. Can you beat this???

Fuel economy is so bad I'm ready to add some gas cans... 25k ago I did plugs, air filter, cleaned the injectors, cleaned the MAF... Tripped the maintenance flag this trip plan on doing all that again as well as new front suspension. Fuel economy is depressing to say the least. I make a regular 1500 mile round trip every month or two and have for almost 30 years. I can no longer make it to my regular fill up stations. I nearly ran out of fuel on the highway today because I just wasn't thinking. Ideas?

 

I did all the back maintenance when I bought the car, there were a lot of issues and it needed a lot of love. It's not really a parts cannon scenario... When I bought the car there was a set of copper core plug on the floorboard so i installed those. I have a new set of iridium plugs to go in and the plan was the next maintenance after 200k, which is where I'm at. I also have my own injector cleaner so I'll do them as I'm basically already there. The car has an aftermarket CAT and the I've had the PO420 code for most of the time I've had the car. never affected fuel economy. The code has now cleared itself.

 

On my 2nd oil change of Valvoline restore and protect. Seems to be quieter and oil consumption is much better. I'm thinking about half as much, it's due now, I'll keep track this next oil change.

 

Seems to be fine otherwise. I just drove from Utah to SoCal. speed limit in Utah is 80, NV 75 and Ca 70. Of course the faster you drive the lower the MPG however this has dropped way off.

Of course the ICE is working way more than the battery.

 

Battery was replaced.

 

the aftermarket CAT was installed before I bought it. it start throwing a code within a few thousand miles of me getting it up and running. I could clear it and it would be gone for a week or more, then only for a day or two and then I just stopped clearing it for well over a year now. Idk exactly why the code cleared itself, my guess is that the CAT got hot enough to clear the code. I’ve only been back in town for a day and the code has not returned, but I suspect it will.

 

only thing I did was do one of the downstream plug fowler hacks when I started driving it and it was throwing the PO420 code. it helped for a time. Whoever put the replacement cat, they did a poor welding job. I had intended to pic up an Amazon CAT one day when I'm out of California. Should do the oil and tune up by Monday... guess I'll see if that helps at all.

 

I actually have a pretty decent OBD2 reader but I was traveling when this happened. I'll be checking all that when I do the tune up

 

I don't want to get into all I've done battery wise DrPrius app shows good battery, but the battery does show an out of range cell, at least compared to all the other cells. I suspect it could be that but I have told it's not, the battery looks healthy. I've seen and calculated as much as 52 MPG in this car. Then did some other "things" and was solid at 42/43 and it's slowly slid down to what I have now 27. One of the reasons I want to remove every other possible issues. again I was planning on doing plugs and such as I got a bunch of parts when advance auto was shutting down a location and bought parts for all my vehicles. At 90% off retail it might be a bit of a "parts cannon" approach but I had planned on doing EVRYTHING it needed at 200K which is where I'm at right now.