19MPG to 30MPG+
 

I sold that lincoln town car we had and bought a 2003 kia rio with the money.
Its a down grade for sure, A/C isn't nearly as strong and you feel a lot more bumps.
On a good day the 4.6L could do 24mpg on the highway. The 1.6L 5-speed kia does 36mpg on the highway with ease.
The first week it coughed up 3 codes, two Oxygen sensor codes for a dead manifold O2 and a converter code.
I replaced the manifold O2 sensor and its still giving a converter efficiency code.

A 10 year old used car... not surprised it may have a few kinks to work out.

Looks like I am going to take off the catalytic converter and work out its major kink.

:thumbup: Wise!

I am also planning on installing taller tires on its 14'' rims.
It has a factory WAI.
Might, maybe, someday install a CAI on a pull cable for getting over the mountains in 5th gear. It cant quite summit some of the passes in the more mountainous parts of NM with out going into 4th.
It also shutters a little when going up the mountains at say 60 to 70 mph at WOT in 5th, almost as if its pulling timing. The CAI should help with that.

Is this sarcasm because mountainous parts of NM aren't really mountainous, or are you being serious? 'Cause I spend a lot of time in 4th gear on hills in my Yaris, being that it's a 1.5 liter engine and all. Your 1.6 isn't really THAT much bigger yano.

Anyway congratulations on the new(ish) car! Downgrading isn't always a bad thing.

They have ok mounitians here in NM, 5% and 6% grades for many miles at a time.
That coupled with thin hot air slows down the vehicles.
The southern part of the state, where I am spending more time now has a lot of hills in the 7,000 to 9,500 foot range.
On the east coast I am use to being able to go over the little mountains there in 5th, most of the peaks never going any where near 4000ft helps.

I price looked up how much it will cost to replace the catalytic converter:
$133 for a universal fit (that I could easily install)
$500+ for a bolt in factory replacement.
Too much $ for something that doesn't make the car go.

Replacing the bad oxygen sensor seems to have fixed the converter efficiency problem.
No more check engine light and I didn't have to do anything else.

It's always nice when a minor fix solves what you thought was going to be a major repair.

Oxy sensors have big impact on FE, especially the faulty ones :)
Congrats on fixing your ride!

I was looking around the under belly of the car today and found that it had an air dam at one time.
Looks like I should try and find or make one.
A nice big air dam should be worth at least 1mpg on the highway and should fix the slight running hot problem it has in traffic.

Looks like you solved your problem with the O2 sensors however if you continue to run into problems, do a search for the spark plug non fouler - O2 sensor trick. Very simple to do. They add a some standoff to the oxygen sensor by pulling it out of the exhaust flow and make the car think the cat is working. My car had the cat removed by a previous owner and that was able to get the CEL to stay off for 40k miles.

I don't like mods like that to be at all visible from the outside.
Usually what I do is cut a little peice of sheet metal and bend it into a cylinder and slip it around oxygen sensor to block most of the exhaust flow going into the sensor.