I have a 2005 grand cherokee 2.7 i changed number 4 injector and battery went flat, recharged it now gearbox gos in 1s n 2en gear nd the code is p0700

SOURCE: Jeep Grand Cherokee Limited P0700 diagnostic problem

P0700 means there is a transmission fault code in the transmission controller. Since the transmission controller doesn't have a light attached, it tells the engine controller to turn the light on using this code. You'll have to access the transmission controller to further diagnose the problem.

SOURCE: 2005 Grand Cherokee Limited Service 4 Wheel Drive Light On

Have the 4wd serviced

SOURCE: 2005 Jeep Grand Cherokee Shifting Problems

Check the Trans fluid level with it running and at operating temperature. Jeep NAG1 transmissions are known to have the input electric seal leak trans fluid. Not an exspensive fix add Mopar ATF4 and then relace the guild seal.

SOURCE: Jeep Grand Cherokee 2.7CRD (2004) auto won't change gear

check all the fuses before you do anything else. After all a fuse provides power to the electronic box that controls the transmission. Other than that I would not advice on a more complicated troubleshooting since there is no way for you to test a bad transmission computer, even mechanic shops don't know how to test them. The only thing they would do is slap a known good one and see what happens.

SOURCE: 2005 jeep grand cherokee trouble code p2096 change

These conditions MUST be ruled out entirely.
Check for any of the following conditions/mechanical problems.
AIR INDUCTION SYSTEM - must be free from leaks
ENGINE VACUUM - must be at least 13 inches in neutral
ENGINE VALVE TIMING - must be within specifications
ENGINE COMPRESSION - must be within specifications
ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks
ENGINE PCV SYSTEM - must flow freely
TORQUE CONVERTER STALL SPEED - must be within specifications
POWER BRAKE BOOSTER - no internal vacuum leaks
FUEL - must be free of contamination
FUEL INJECTOR - plugged or restricted injector; control wire not connected to correct injector.

Unfortunatly, a scan tool will be required to monitor o2 sensor voltages while the engine is running in closed loop. This code you are displaying is NOT an easy solution to trace down. I expect you had an exhaust leak and is why the cats were replaced? Anyway, if so, the PCM can reset the light after a few GOOD trip readings occur that will satisfy the PCM's no fault signal, otherwise the JEEP dealer is going to be your only solution and a pressure test should be performed.