Dylan Urban

I have a 1992 jeep with a 4.0 aotumatic. I had a shop replace my tank, fuel pump, straps, fuel filter and the one 02 senors. I was getting like 12 miles to a gallon. Before this I had a leak in my tank but was getting roughly 18. So i replaced the injectors with 12 hole ksusepion injectors and and replaced theromas. Now i am getting 8 miles to a gallon. It ildes around a 1000 rpms and when i start it when it is warm it spaters a little.

DJXJ97

If you install bigger injections and the engine isn't tuned to run with them, you're bound to have issues. It is most likely dumping way more fuel into the cylinders than it is supposed to. This is causing it to run very rich and probably causing the plugs to foul and misfire, and also burning up more fuel that you aren't using. The easiest and cheapest way to at least help this issue would be to get a better flowing intake to help get some more air into the mixture, but you should probably go back to OEM injectors or get a tune.

PatHenry

Did the shop use an NTK O2 sensor? If not I'd pull that sensor and replace with an NTK.

Also check the wiring to your sensor and the CTS.