ON A 2001 ISUZU TROOPER 3.5 LITER ENGINE, I NEED A DIAGRAM OR PICTURE OF THE EGR PORTS SO I CAN TRY TO CLEAN OUT THE CARBON DEPOSITS.

Clean throttle body and passages also check egr ports and valve operation. Look for carbon build up and clean with carb. Cleaner spray can if deposits found...do not spray egr valve as if it enters the diaphragm it will ruin the vaccume diaphragm.

get a workshop manual from any auto parts shop
the engine and what you are after will be common for any vehicle that has the same engine family

When you say you cleaned the ports which ports did you clean.? These engines are very sensitive and do build up lots of carbon on the small egr vacuum ports. The focus here is usually the vacuum port inside the intake manifold that is behind the throttle body. Take the throttle body off and look inside you will see usually a big deposit of carbon where the port is to be. That needs cleaned. You also need to check the vacuum line that runs from the intake manifold over to the right strut tower. This goes to your boost sensor solenoid. Make sure that that line has good engine vacuum. If it does not clean that port as well. If that line is clogged I have seen the carbon get so bad that it clogs the boost sensor solenoid and the vacuum line after the solenoid. All of these ports need cleaned not just one.

The throttle body is coated with a sludge resistant material. If you cleaned it all out you are actually hurting your engines performance, because the throttle body resists sludge which in turn protects your throttle plate and bore. You may want to check your egr vacuum regulator, for the cause of your problem.

I have a 2000 Isuzu Trooper that had a PO401 code that would reset and then 2 miles later the light was on again - I found if you remove the EGR valve and start the engine that the engine should idle rough - If it doesnt and you have vacumn at the intake port spray carb cleaner down the port slowly and see how long it takes for the engine to run rough - Keep spraying till the engine dies and spray some more down the passage and let the engine set for 5 minutes and then restart the engine - it will run rough at first but clear out - you should be able to feel the engine RPM change when you put your finger over the intake vaccumn port for the egr - If not then repeat the cleaning method again - If you do feel the rpm change then put the egr valve back on and clear the code and run your drive cycle to see if it is fixed.

on petrol V6 engine its right rear side of inlet manifold(left side when looking into engine bay) see pics. below
diesel its on inlet manifold left side middle section of manifold

You have to the EGR valve (sometimes the Intake manifold to EGR Vlalve line also). After you remove it take a drill bit the about 20 % smaller than the actual hole of the outlet side and rotate the drill bit with your hand to dig out the carbon. Aditionally the line coming from the intake manifold to the EGR valve will clog near the connection to the EGR valve. I use either a single piece of copper wire or the wire that you would use to tie ribar together to clean the line. When your done cleaning take a piece of vacuum line and connect it to the diaphram side and **** on it... then plug the line well with your thumb. Grasp the valve and blow thru it... Air should blow thru it freely. Remove your thumb from the vacuum line and try blowing again.. No air should pass thru the valve.
Then reinstall the valve and start the vehicle with the vacuum line disconnected (but blocked off) Use another piece of vacuum line connected to the diaphram again and **** on the line.. The vehicle should die or run really bad. If it does this then you cleaned it correctly.

probably engine light cannot be erased by disconnecting battery

you need a code reader(at Garage) to erase and check code

Look on Auto Zone's website for a picture of the EGR valve....usually located near the top rear of the engine. You can try cleaning the EGR with some carburetor cleaner as they usually get pretty fouled up with carbon deposits, just remember to replace the gasket when after you remove it. If cleaning the EGR does not help, you may need to replace it.

yes they have 2 cataletic convertors, one each bank
there is EGR codes, but only front O2 sensor codes and fuel trim codes no CAT codes
what were the scanner codes or flash codes i can work with both for helpful info
you can read codes by bridging pins 5 & 6 with ignition in on position engine not running