1997Jeep cherokee sport 8 mpg/ check engine light

I have a 1997 Jeep Cherokee Sport with 150,000 miles. I figured up that I am getting 8mpg on a good day. The check engine light is on but I think that is because there is no cadillac converter.I have changed the spark plugs and the oil within the past month. It also takes a minute to start up and when first accelerating it putters and slows to a stop and then you hear a pop and it takes off again. When I changed the spark plugs that problem went almost completely away but at times it comes back. Also the other day I filled up at a gas station and after filling up I attempted to start the car and could not. After a few tries it finally started but everytime I took my foot off the gas it would shut off. My main concern is the gas mileage and I would just like to know if I need to search for a new vehicle. thanks.

If your vehicle lacks a catalytic converter and you never had the ECU reprogrammed to turn off/ignore the O2 sensors or you never procured MIL eliminators to “trick” the ECU into thinking that the O2 sensors are sending a normal signal to the ECU, then your engine is running in open loop mode. This can cause significant drop in fuel mileage (around 30% in many cases).

Them Cadillac converters will get you every time.


That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

am i way out in left field thinking this may be a timing issue?

There’s no point in messing with anything regarding the gas mileage if you’re driving around without a catalytic converter.

Thank you this is very helpful. I asked the person who I bought the jeep from exactly what happened to the converter and they said the cord that comes out of the catalytic converter is missing. As you can tell I don’t know much about vehicles and I am just trying to keep from being without a vehicle. I bought it about 6 months ago from a friend and it was a few months before that when the converter got messed up. obviously this friend was as incompetent as I am regarding vehicles. Can anyone tell me how much this might cost me? Thanks again

what do you mean?

I wish I knew what any of that meant. =)

I will try to find someone around here to do that for me thanks for the advice

Let me decode FoDaddy. Your engine’s computer controls how much fuel goes into the engine to burn. It has to use information from the oxygen sensors to adjust the fuel delivery. For each bank of spark plugs you have 2 O2 sensors - one is before the catalytic converter and the other is after the catalytic converter. You don’t have a cat so the whole feedback system for fuel delivery is a wreck. As such, there isn’t much point in chasing fuel economy problems with a known large issue.

Catalytic converters are not cheap and who knows what other kinds of butchering have been done. Find a local, independent shop - preferably one that does a lot of exhaust work - and take it to them for a once over and an estimate.

I mean the way it starts and runs sounds like the timing could be off