To resent the timing on a 1997 3.0L Chysler engine, can you take the timimg belt off and turn the camshaft spockets to 12 degrees BTDC

Question edited for clarity. Did you know typing in CAPS is considered shouting, plus it is harder to read.
Question moved to model category.

The EGR valve is located in the engine compartment (underneath the hood). Most engines require exhaust gas recirculation to meet emissions standards.

GMC Yukon XL 1500 Exhaust Gas Recirculation/EGR Valve ...

Doesn't have a EGR valve ! Has Camshaft Actuator System .
Camshaft Actuator System Description
The camshaft position (CMP) actuator system is used for a variety of engine performance enhancements. These enhancements include lower emission output through exhaust gas recirculation (EGR) control, a wider engine torque range, improved gas mileage, and improved engine idle stability. The CMP actuator system accomplishes this by controlling the amount of intake and exhaust valve overlap. For the 6.0 liter (LY6, L76) and the 6.2 liter (L92) engine, the Park position for the CMP actuator and camshaft is 8.5 degrees before top dead center (BTDC) or 17 crankshaft degrees BTDC. The engine control module (ECM) can only command the CMP actuator to retard the valve timing from the Park position or advance the valve timing back to the Park position. The total range of valve timing authority is 31 degrees camshaft rotation, or 62 degrees of crankshaft rotation. The control range is from the Park position of 8.5 degrees camshaft or 17 degrees crankshaft BTDC, to 22.5 degrees camshaft or 45 degrees crankshaft after top dead center (ATDC).

You have 2/4/6 timing marks 180 degress out on exhaust or intake cam .

Did your special tool ?
Rotate the crankshaft using the J 42098 until the #1 cylinder is at 60 degrees before top dead center (BTDC).
Install theJ 42069 Crankshaft Locking Tool.
Rotate the crankshaft in the engine rotational direction (clockwise) using the J 42098 until the #1 cylinder is at top dead center (TDC) and tighten the lever arm to the water pump pulley flange.
Important: Ensure that the alignment of the crankshaft is not 180 degrees off. The alignment mark must align with the corresponding notches on the rear timing belt cover.
Install the 1-2 and 3-4 camshaft locks, the J42069-1 Timing Belt Alignment Kit and the J42069-2.
Important: Do not rotate the crankshaft if the camshafts are not locked in place with the 1-2 and 3-4 camshaft locks (J42069-1 and J42069-2).
Important: Do not rotate the camshafts unless the crankshaft is at 60 degrees BTDC or the valves may contact the crankshaft.
Loosen the tensioner pulley.
Remove the timing belt.

Doesn't have or need an EGR valve it has Camshaft Position (CMP) Actuator System
The camshaft position (CMP) actuator system is an electro-hydraulic operated device used for a variety of engine performance and operational enhancements. These enhancements include lower emission output through exhaust gas dilution of the intake charge in the combustion chamber, a broader engine torque range, and improved fuel economy. The CMP actuator system accomplishes this by changing the angle or timing of the camshaft relative to the crankshaft position. The CMP actuator simply allows earlier or later intake and exhaust valve opening during the four stroke engine cycle. The CMP actuator cannot vary the duration of valve opening, or the valve lift.
During engine OFF, engine idling conditions, and engine shutdown, the camshaft actuator is held in the park position. Internal to the CMP actuator assembly is a return spring and a locking pin. During non-phasing modes of the camshaft, the return spring rotates the camshaft back to the park position, and the locking pin retains the CMP actuator sprocket to the camshaft. The park position for the CMP actuator and camshaft is 8.5 degrees before top dead center (BTDC), which is equal to 17 crankshaft degrees BTDC. The engine control module (ECM) can only command the CMP actuator to retard the valve timing from the park position, or advance the valve timing back to the park position. The total range of valve timing authority is approximately 20 degrees of camshaft rotation, which is equal to 40 degrees of crankshaft rotation.
CMP Actuator System Operation
The camshaft position (CMP) actuator system is controlled by the engine control module (ECM). The ECM sends a pulse width modulated 12-volt signal to a CMP actuator solenoid to control the amount of pressurized engine oil, into the CMP actuator. To regulate the pressurized engine oil into the CMP actuator, the solenoid uses electromagnetic force on the solenoid pintle to pulse the oil control spool valve. The pressurized engine oil is sent to unseat the locking pin, and to the vane and rotor assembly of the CMP actuator, to either retard or advance the valve timing. The ECM will control the amount of ON time applied to the solenoid.

I just recently experienced the same problem. The timing is 180 degrees out. Unfortunately the only way to correct it is to take the engine apart again. Set the right hand camshaft to TDC by using the marks on the timing gear for that bank. The left will follow to the degree it can although you will have to manually hold the cam in position when you put the timing gear back on. Now you can remove the timing chain. The crank TDC indicator may not be right on but it will be close. Rotate the crank CW one revolution to the point the TDC marks are lined up. Now install the timing chain according to the instructions. The timing gears on the camshafts will only go on one way as the bolt holes are slightly off the extreme diameter of the gear. If you put the chain back on making sure that all the marks are proper, she'll fire on the second cylinder up. Not a fun job I know, but when everything works right, you do get a sense of satisfaction.

Installation
1.Install No. 2 idler pulley (if removed). Install and tighten bolt to specification. See TORQUE SPECIFICATIONS . Ensure idler pulley is clean and rotates smoothly. 2.Install No. 1 idler pulley and tension spring (if removed). Pry No. 1 idler pulley away from timing belt area as far as possible. Temporarily tighten No. 1 idler pulley bolt. Ensure idler pulley is clean and rotates smoothly. 3.Using crankshaft pulley bolt, rotate crankshaft so timing mark on crankshaft sprocket aligns with timing mark on oil pump housing. See. This will position keyway in crankshaft sprocket at 12 o'clock position.

CAUTION:If reusing timing belt, ensure reference marks on timing belt align with reference marks placed on crankshaft and camshaft sprockets. Ensure timing belt is installed in original direction of rotation.
4.Ensure all sprockets and idler pulleys are clean. Install timing belt on crankshaft sprocket, oil pump sprocket, No. 1 idler pulley, and then No. 2 idler pulley in sequence. 5.Install timing belt guide with cupped side away from crankshaft sprocket and flat side toward timing belt. Install No. 1 timing belt cover and new gasket. 6.Align crankshaft pulley key groove with key in crankshaft. Install crankshaft pulley. Install and tighten crankshaft pulley bolt to specification. 7.Rotate crankshaft clockwise so cylinder No. 1 is at TDC on compression stroke. Ensure timing mark on crankshaft pulley aligns with "0" mark on No. 1 timing belt cover. If reusing timing belt, ensure reference mark on timing belt aligns with upper edge of No. 1 timing belt cover. 8.Rotate camshaft, and align hole in camshaft sprocket with alignment mark on camshaft bearing cap. See Fig. 2 . Install timing belt on camshaft sprocket. If reusing timing belt, ensure reference mark on timing belt aligns with the reference mark on camshaft sprocket. Ensure tension exists on timing belt between the crankshaft and camshaft sprockets.
CAUTION:DO NOT rotate crankshaft counterclockwise, as viewed from timing belt end of engine.
9.Loosen No. 1 idler pulley bolt 1/2 turn. Rotate crankshaft pulley 2 full revolutions clockwise from TDC to TDC. 10.Ensure timing mark on crankshaft pulley aligns with "0" mark on No. 1 timing belt cover, and hole in camshaft sprocket aligns with alignment mark on camshaft bearing cap. See Fig. 2 . If timing marks are not aligned, remove timing belt and reinstall. 11.Rotate crankshaft clockwise 1 and 7/8 revolutions and align crankshaft pulley "0" mark with 45-degree Before Top Dead Center (BTDC) mark on No. 1 timing belt cover. See Fig. 5 . 12.Tighten No. 1 idler pulley bolt to specification. See TORQUE SPECIFICATIONS . Install No. 2 timing belt cover and gaskets. Install and tighten spark plugs to specification. 13.To install remaining components, reverse removal procedure. Install all bolts/nuts on right (timing belt side) engine mount before tightening to specification. 14.On Camry, when installing control rod and bracket on strut tower and right (timing belt side engine mount, tighten bolts to specification in sequence.

Timing Belt & Sprockets Removal & Installation 3.2L Engine To Remove:
TDC compression stroke timing marks

1. Before servicing the vehicle, refer to the precautions at the beginning of this section.
2. Remove or disconnect the following:
   • Timing belt cover
   • Crankshaft damper
3. Rotate the crankshaft in the engine rotation direction, clockwise using the J 42098 or other suitable tool until the # 1 cylinder is at Top Dead Center (TDC) on the compression stroke. The reference marks on the camshaft gears should be aligned with the corresponding notches on the rear timing belt cover, as well as the mark on the crankshaft sprocket and oil pump housing. Timing marks 60 degrees from TDC
   
   
4. Rotate the crankshaft counter clockwise using the J 42098 or other suitable tool until 60 degrees Before Top Dead Center (BTDC). The 60 degrees BTDC point can be identified by the index mark on the oil pump cover. Using the J 42069-10 or other suitable tool
   
   
5. Install the J 42069-10 or other suitable tool to the crankshaft sprocket with the knurled bolt.
6. Rotate the crankshaft in the engine rotational direction, clockwise using the J 42098 until the lever of the J 42069-10 or other suitable tool firmly contacts the water pump pulley flange. The # 1 cylinder is at TDC at this point.
7. Secure the moveable lever of the tool to the water pump pulley flange. Tools in cam gears
   
   
8. Install the J 42069-1 and the J 42069-2 or other suitable tools to the camshaft gears. If the J 42069-1 or the J 42069-2 or other suitable tools do not fit into the teeth of the camshaft gears, it may be necessary to loosen the upper idler pulley and turn the eccentric or camshaft gears until the tool can be inserted.
9. Loosen the timing belt tensioner nut.
10. Loosen the upper idler pulley bolt.
11. Remove or disconnect the following:
    • Lower idler pulley bolt
    • Lower idler pulley and spacer
    • J 42069-10 or other suitable tool from the crankshaft sprocket WARNING
      After timing belt is removed, never turn camshaft and crankshaft independently. Do not remove J 42069-1 and the J 42069-2 or other suitable tools while the belt is removed.
      
    • Timing belt

To set the timing the engine must be at operating temp, with car at idle remove vacuum line from the disturbutors vacuumadvance valve on the side of distributor and plug vacuum hose next with a timing light connected to battery and # 1 cylinder check the timing it should be at 8 degree btdc, i gave you a picture of timimg pointer and crank,it needs to be at 8 degrees, if not loosen cist hold bolt and turn dist to get 8 degrees. move slowly while watching with light. hope this helps.

A factory service manual would help, but I'm assuming that if you had one, you probably wouldn't be on this site.

To set the timing, you need to first perform the obvious: remove the accessory drive belts, cam pulley covers, and engine fan and hub. Next you'll need to rotate the engine by hand until the timing marks on the camshaft sprockets and crankshaft are aligned with their corresponding stationary marks. The 0 degree mark on the lower timing belt cover is the timing mark for the crankshaft pulley. There is a mark (small, vertical formed indentation) for the left camshaft pulley on the backing plate behind the pulley near the 1 o` clock position. The same mark exists for the right camshaft pulley only it is on the backing plate near the 8 o`clock position (making it difficult to see). With the crankshaft placed at the zero mark, you can observed where the timing discrepancy exists.

(TIP: Once the right camshaft timing is properly lined up, etch an additional mark on the pulley's face and the backing plate at the 12 o`clock position. This will make it easier to align the pulley for furture adjustments and repairs)

To set the timing correctly, move the crankshaft pulley to 12 deg. BTDC. Being careful to not disturb the position of the crankshaft once it has been moved to that position, remove the crankshaft pulley, lower timing belt cover, timing belt tensioner, and timing belt. Compress the timing belt tensioner and if the original ring pin isn't available to retain the tensioner a small allen wrench can be used to achieve the same results. Line up both camshaft marks and reinstall the timing belt and timing belt tensioner (do not remove the timing belt tensioner tool used to maintain the tensioner piston in a compressed position). When installing the timing belt, be sure to allow the least amount of slack to exisit between the left camshaft pulley and the crankshaft sprocket, but without moving the pulleys.

Next, remove the timing belt tensioner piston retention tool and mount the lower timing belt cover and crankshaft pulley (without fully installing them). Rotate the crankshaft pulley to the 0 deg. mark. If done correctly, moving the crankshaft pulley from 12 deg. BTDC to 0 deg. will remove all remaining slack from the timing belt assembly and the camshaft pulleys and crankshaft pulleys will be lined up with their corresponding marks. Once proper timing has been achieved, install all removed parts.

(Another TIP: I hope it's not necessary, but in case it is, I'll remind you that proper torque of all bolts are necessary as this is an all aluminum engine. Stripping out bolts holes due to over-tightening bolts occurs very easily and become very annoying to deal with [e.g. alternator belts not being able to be tightened completely and constantly squealing every few days, etc.])

What you do is line up the lower mark. Go to the upper sprocket and move the sprocket 1 tooth back(counter clockwise). After the belt is on, Rotate ONLY the upper sprocket to take up the slack in the long side of the belt being careful of not moving the lower sprocket. The upper spocket should now be exactly where it should be. Release the tensioner and I like to use a big screw driver or something to "preload" the tensioner before fully tightening it. The belt should have really good tension. The rule of thumb is the long side of the belt should not be able to twist 90 degrees to the engine. If it's more that that, ou need to tension it up tighter.