Toyota camry 96 model 220. i have overalled the engine and niw i cant get compretion. I have done a compretion test on the head and it is right. What els can be the fault

SOURCE: 2003 toyota camry

P0420 is a cat code. Sometimes, you can replace the upstream & downstream air/fuel & O2 sensors, run some good fuel injection cleaner thru it, and that might fix the problem. If not, you may need to replace the cat. Note that the cat is covered under warranty for 8 yrs/80,000 miles. Toyota will replace it if it has gone bad, for free.

SOURCE: 1993 Toyota Camry V6 Timing Settings

Get a T belt from toyota. It has 3 white lines on it and and arrow mark. 2 lines are solid and one is broken. Put the arrow facing away from the engine. The cam gears have a dot punched into them near a certain tooth. This is where the solid white lines will line up with. The crank gear will have a dot also. It will line up at 90 degrees from the top, towards the front of the car. This is where the broken line will match up with. With the belt installed with all lines on their proper dots and arrow away from the engine, you valve timming is correct.
Of course you need to remove and compress the tensioner also. I assume you know this already since you didn't ask.

SOURCE: HOW TO SET TIMING ON 96 TOYOTA CAMRY 2200 MOTOR

Click on the following free direct Link. It has the Timing: Pulley, Belt and Mark Diagrams for your 1996 Toyota Camry. Plus additional Instructional and Directional Diagrams.

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!

http://www.2carpros.com/car_repair_information/year/1996/make/toyota/model/camry/1996_toyota_camry_timing_belt_diagram_marks.htm