Topic: Engine swap/check engine light?

[spacoli]

I'm recently replace the engine in a 93 p-u with a used engine (100,000mile).
My check engine light is on, so I did some research and did the jumper wire in the diagnostic box and got a two digit number, 21. Which has to do with the O2 sensor.

I'm not sure if the light was on previous to replacing the engine, since I did not own or run it.


I have been checking my gas milage and I'm getting 17mpg (city/highway), which doesn't seem to be off the norm from what I read. I would like to get more MPG if possible. I have a highway trip coming up and plan on checking highway mpg.

Should I have a shop do a diagnostic check to make sure I need a O2 sensor before I go replace it. If I do replace it, will the check engine light go off if that was the problem or will the shop need to clear it off?

Thanks

[spacoli [OP]]

Just got back from a 240 mile road trip. Average speed of 45 mph GPS reading (traffic jam at rush hour hurt that avg.) Pretty much highway running with one mountain to go over both ways. My mpg come in at a few decimals over 24 mpg.

I was pretty surprised to get that high on mpg. I was expecting 20mpg, maybe 21mpg.

I still think it can run better, it seems to have a hesitation or bog at lower rpm in 2nd and 3rd gear while accelerating. I can best describe it, like a two stroke motorcycle when hitting the "powerband". Until you hit the powerband it seems boggy, but once your in the powerband your good.

I still have a low idle also.

Does this make since at all?

I really don't know how or what to expect this truck to run like, since I have not driven one before.

What do you guys think?

[BLACKDOG]

3.0?  22re?  the 17mpg sounds like a 3.0, even up to the 21 mpg, but 24?   

[spacoli [OP]]

Sorry it's a 22re.

[All_Set]

Do you have larger than stock tires?  Is speedo calibrated for those tires?  That will throw off actual miles driven.

24mpg is good! 

[spacoli [OP]]

I was very surprised also.

Standard size tires. I took along my GPS. The odometer milage (224)was only 10 miles difference from 234 miles (GPS). I used the odometer mileage to calculate.

Every time I fill the tank at the pump, I let the pump shut off by itself so I get the same amount of gas.

My three previous checks ranged betwen 16.75 - 17.75. That was mostly stop and go driving with some 15 mile streches of highway.

I'm fooling around with the timing, someone suggested that it might be off a little. I had initially set it to 5* with the jumper installed. I'm going to try advancing it a bit and see if that helps my low rpm bog. I don't have a light, I have to borrow one.