jacked_xj

My CEL code is p0174...,

My oil pressure is still all the way up.. but I don't have a cracked head gasket. Not to mention I got 10 mpgs on my first tank and 5 on the last... fillin up today. It's a 00 4x4 i6.

jacked_xj

Here's the print out

jacked_xj

Anyone?....

thundaluvin

well by the looks of the printout, you have a faulty O2 sensor. Start with replacing that and have it rechecked.

jacked_xj

Would a bad 02 sensor effect my mpg...? It also says somethin about fuel pressure, or maf sensor. What could I do about the fuel pressure?

jacked_xj

Gas cap?

SteelBlue99

Just noticed the receipt and it said "Albuquerque, NM". I'm in ABQ also. Faulty O2 sensor would definitely effect MPG. I'm getting ready to change mine as well. Tired of getting 10-11 MPG average. Mine just hasn't thrown a code yet. I would definitely change that first and see what happens.

jacked_xj

Yeah I couldn't believe this last tank insane. I'll do mine tonight I hope. How much are they?

SteelBlue99

If you get them from AutoZone, i believe they run $50-55. Somewhere around there. I think mine is starting to fail, but hasn't compeltely. Is your Jeep completely stock?

jacked_xj

Yeah for now. Doesn't stop me from takin it out tho. And 50 bucks for a sensor!? Lol wow. Future plans are 6.5 in long ARM from rc, on some 35in Goodyear duratracs.

dukie564

whoh whoh, before you start throwing parts at it, let's understand what that code means.

It indicates the a/f mixture is too lean. Yes this could mean that the upstream (pre-cat) o2 sensor is malfunctioning and needs to be replaced, but i would eliminate the other possibilities before throwing money at it, otherwise the problem could come back.

Since it is reading too lean, the ecu is bumping up your fuel to compensate, thus the gas mileage loss. But WHY is it reading too lean?

I would start by checking to see if you have any leaks - most common are around the throttle body (see if it's loose), and especially due to a cracked exhaust header (very common to crack near the necking point). A leak would add that extra oxygen that is throwing the code.

You need to fix the cause first. If you replace the o2 sensor because it's all carboned up from running rich, and you don't solve the problem causing it, the new one will fall to the same fate a few weeks/months down the road.


Another thing to check before replacing the sensor is the heater circuit fuse. It's in the PDC (underhood fuse box), 15amp mini fuse (i forget the number).

SteelBlue99

For a stock Jeep 5-10 MPG's is TERRIBLE. $50 is worth the cost it will save in gas. I love my DuraTrac's! When these tires are done, i'm probably going to go up to either 5.5" or 6.5" of lift and 33's, possibly 35's.

jacked_xj

Ok. So first check for leaks near the throttle body than the header.. does this mean I need to take my intake mani off! Ugh.. and what are u running now?

dukie564

no you don't have to take anything off. You'll be able to see if the header is cracked. Leaks around the throttle body you'll be able to hear it or spray some carb cleaner around it and see if the idle RPMs go up.

This is where the headers like to crack:

jacked_xj

Ok sounds good. I hope its just a loose throttle body (wishful thinkin).