1999 jeep cherokee 6 cylinder engine light

no engine stated.??????????
303 is gross misfire on #3 cylinder. on all cars.
its a for sure thing, means bad combustion on #3 and its power is weak. 1763 is tranny The 7 means that. and is problem2.

ever get a 60k miles tunup this decade?
sparks plugs, spark wires, filters, air and fuel>?
spark plugs dont last life of any engine.
THE CEL blinking (oper guide tells) means that misfire
is burning the CAT converter to a crisp. (raw fuel + air does that)
the opr. guide says get it serviced, fast, dont drive fast or tow anything. all great advice in the glove box.

get a cheap tuneup, and magic can happen in most cases.
misfire has many causes. over 20.
but a tuneup not done, is 99% cause. (due to nobody doing them)
only fate , determines truth, not statistics....
for example you sucked a valve on #3..

if the new spark parts dont fix #3 a compression tests is next.
or an injector balance test say from #3 to one other injector.
all this is like 1hr work, but no engine stated, so.....

p0303 is a mutible engine misfire on number 3 cylinder. the best fix,

A code P0303 may mean that one or more of the following has happened:

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• but first of all check the wires and sparkplugs first!

Check engine light is a signal that the ecu has detected a trouble code from some sensor in the vehicle. Have the trouble codes read to find out exactly what's wrong.

Misfire on cylinder #3 -- http://www.obd-codes.com/p0303

Plug, plug wire, plugged or open fuel injector. are the most likely.

Check spark plug wires for corrosion

Sounds like you have a fuel pump or distributor gas and or spark not getting to engine.

I guess the best place to start is change plugs and wires. A timing light would come in real handy. You could check to see if you had spark on all cyllinders before you start blowing cash. If you have spark in the wires, then change plugs. If theres no spark in the wires, then the problem is before that. Like coil, or idle control sensor etc. Keep me posted and i'll try and help as much as possible. Not much a keyboard can do.

Your right about the two codes. It's really a transmission part.
As soon as you open up the transmission pan, it right there.
But, I would leave this up to a transmission place. It may need a special type of calibration tool for the new sensor.

As for PO303, that is a missfire in cylinder #3

I hope I answered your question.

Check the cylinders Commpression. over 115 psi is good, 120 psi is normal.