GM 24503125
Cross Over

The full one-piece combination of Muffler and tailpipe needs replacement during Catalytic Converter servicing. To start your work remove the Oxygen Sensor followed by supporting the converter. Start by removing nuts attaching the front pipe to Catalytic Converter then proceed to detach intermediate pipe hangers located at body mounts before finally removing the rear hanger at the tailpipe to chassis mount. Remove the entire exhaust system from the vehicle once you finish that step. The exhaust system needs support at the converter point before setting it in line with the vehicle's underbody. Begin screwing the converter studs' nuts through the front pipe flange alignment by following the fastener notice from service precautions. Connect the center Exhaust Hanger to the underbody and fasten it with torque of 30 nm (22 ft. Lbs.), before connecting the rear Exhaust Hanger to the rear compartment rail and tightening to 50 nm (37 ft. Lbs.). Apply torque to the front pipe converter nuts until they reach 25 nm (18 ft. Lbs) before finally installing the Oxygen Sensor (Heated Oxygen Sensor (HOS) replacement).

The first step to work on an Exhaust Pipe requires vehicle suspension followed by support. When dismounting the flex coupling from its standard position protect both the flex coupling and pipe assembly from excessive flexing because the marriage of parts can flex only up to six degrees and this equals a maximum movement of one inch per one foot of pipe size and thus a three-foot pipe reduces to a three-inch flexible range. The sequence for replacement involves removing two nuts from the Exhaust Manifold while removing four nuts from the Catalytic Converter before finally removing the exhaust downpipe. Start by attaching the downpipe to the manifold with its gasket before screwing the front pipe onto the manifold studs according to the service precaution fastener notice. Secure the four Catalytic Converter nuts to 25 nm (18 ft. Lbs.) before proceeding to bolt the Exhaust Manifold studs and tightening them to 50 nm (36 ft. Lbs.). Finally, lower the vehicle.

The Catalytic Converter necessitates the need for changing the Muffler and tailpipe as a whole unit. The process should be started with the Oxygen Sensor (H02S1) removal. Support the converter, then remove the front pipe to Catalytic Converter nuts, next the intermediate pipe hangers at body mounts with the others (rear hanger) at tailpipe to chassis mount. Then, the exhaust system should be removed from the vehicle. In case of installation, support the exhaust system at the converter and align it to the under body of the vehicle. Install the converter to the front pipe flange and tighten the nuts on the converter studs. Attach the center Exhaust Hanger to the underbody and the rear Exhaust Hanger to the rear compartment rail. The front pipe to converter nuts then are to be tightened to 25 nm (18 ft. Lbs.), and finally the Oxygen Sensor h02s1plug in.

The work on an Exhaust Pipe starts by raising the vehicle and providing support. The Catalytic Converter must be detached from the Exhaust Manifold pipe through removal of its four securing nuts. The exhaust system should set behind the studs that exist at the Catalytic Converter front region to prevent any blockage of the Exhaust Manifold pipe. Disassemble the Catalytic Converter gasket and discard it before taking out the Exhaust Manifold pipe's two nuts which connect it to the right Exhaust Manifold. People should remove both the Exhaust Manifold pipe and its gasket because they will not be placed back on the vehicle. Position the Exhaust Manifold pipe properly against the right Exhaust Manifold and slide a new Exhaust Manifold pipe gasket across the right Exhaust Manifold studs. Position the Exhaust Manifold pipe to its place on the right Exhaust Manifold and securely tighten both nuts to 40 nm (30 ft. Lbs.). Place a new Catalytic Converter gasket onto the studs before setting the Catalytic Converter to fit with the Exhaust Manifold pipe. Install and tighten four nuts to 25 nm (18 ft. Lbs.) while keeping the Catalytic Converter in position. Finally, lower the vehicle.

Replacing the Catalytic Converter heat shield is such that you must remove the exhaust system while making sure there is eye protection on to prevent injuries when drilling together the rivets. Drill the center of heat shield rivets, pull down on heat shield to help it break free from keeping stud and slide to left under oxygen sensor wiring harness heat shield. When installing, place the heat shield by sliding it to the right under the oxygen sensor wiring harness heat shield, slide upward over retaining stud, align on the floor panel hole in heat shield so that it's in line with the hole in the floor panel. This necessitates the use of a rivet gun to secure both the oxygen sensor wiring harness heat shield and Catalytic Converter heat shield to the floor panel with single rivet and securing all the remaining rivets before the reinstallation of the exhaust system.

The exhaust crossover replacement starts by unplugging the fuel injector sight shield followed by gentle detachment of the throttle body air inlet duct while removing the air cleaner assembly. Start by removing each heat shield nut from the exhaust crossover followed by the heat shield and then proceed to uninstall the crossover pipe bolts and finally the pipe. When replacing the exhaust crossover pipe also remove its associated seal. Start by applying the exhaust crossover pipe seal onto the exhaust crossover pipe that connects to the right exhaust manifold before installing the pipe. Insert the exhaust crossover heat shield then secure its nuts to 20 nm (15 ft. Lbs.) before tightening the exhaust crossover pipe bolts to 18 nm (13 ft. Lbs.). You should put the throttle body air inlet duct back and then reinstall the air cleaner assembly after which you should mount the fuel injector sight shield.

The first step to replace the exhaust crossover pipe on a 3.8l engine includes removing the fuel injector sight shield followed by the throttle body air inlet duct before removing the air cleaner assembly. Begin by removing exhaust crossover heat shield nuts before taking away the heat shield and continuing with the exhaust crossover pipe bolts to separate its connection with the pipe and seal. The first step for installation should be to connect the exhaust crossover pipe seal onto the exhaust crossover pipe at its right exhaust manifold connection and then attach the exhaust crossover pipe. Secure the exhaust crossover pipe with 18 nm (13 ft. Lbs.) torque setting while you install the exhaust crossover heat shield and fix it using heat shield nuts that need to be tightened to 20 nm (15 ft. Lbs.). The completion of the installation requires the throttle body air inlet duct followed by careful reinstallation of the air cleaner assembly before finishing with the fuel injector sight shield.

To replace the three way Catalytic Converter, initially lift and properly supported the vehicle. Unplug and unbolt the heated Oxygen Sensor wiring harness connector and retainers. Make sure that before you remove the bolts and gasket holding the Catalytic Converter in place that the exhaust system has proper support. Then, unlatch the exhaust manifold pipe stud nuts and the three way Catalytic Converter, and the exhaust manifold pipe gasket at exhaust manifold pipe studs must also be removed. Remove the heated Oxygen Sensor. For installation, you can start by installing the heated Oxygen Sensor and another new exhaust manifold pipe gasket to the exhaust manifold pipe studs. Support the three way Catalytic Converter and fasten the exhaust manifold pipe with stud nuts using 35 nm (26 ft. Lbs.). Install the Catalytic Converter Gasket and bolts by putting bolts tension of 45 nm (33 ft. Lbs.). Reconnect the heated o2 sensor wire harness connector and retainers, remove the support from the exhaust system, check for leaks and underbody contact, and finally, lower the vehicle. You should always replace the gaskets on the front and rear flanges when you service the Catalytic Converter assembly and never fit the orignal gasket.

One should start the Exhaust Pipe replacement process by properly lifting the vehicle and securing it with appropriate support while following all vehicle lifting procedures. The exhaust system needs proper support before disconnecting the insulators from the Exhaust Pipe. To obtain sufficient overlap before clamping the cut should be made precisely 38 mm (1.5 Inch) from the mufflers right before removing the Catalytic Converter bolts and gasket. First separate the Exhaust Pipe from exhaust mufflers through the cutting process before removing it from the vehicle. Installation starts with clamping the inlet pipes of the exhaust mufflers but skipping nut tightening steps at this time. Position the Exhaust Pipe under the vehicle by supporting it and make the attachment to the mufflers. Follow the fastener guidelines while installing the Exhaust Pipe to the insulators and alighting the entire exhaust system. The process starts by torquening exhaust Muffler inlet pipe clamp nuts to 50 nm (37 ft. Lbs.) then continuing with a new Catalytic Converter Gasket and Catalytic Converter bolt installation at a torque value of 45 nm (33 ft. Lbs.). The process ends when you first inspect for leaks then examine the underbody contact while simultaneously lowering the vehicle.

It is a necessity to replace the whole assembly to service the three way Catalytic Converter, using a new gasket at the front flange, always refittings, never refitting the original. Start by lifting and holding the vehicle. Remove the heated Oxygen Sensor electrical connector, take out the exhaust manifold pipe studnuts before removing the Catalytic Converter bolts, prior to you removing the three way Catalytic Converter. Then, take off the heated Oxygen Sensor (H02SI or HO2S2). Install it first by installing the heated Oxygen Sensor (HO25 or HO2S2) then install a new exhaust manifold pipe guitar. Make sure to support the three way Catalytic Converter and bolt the Catalytic Converter. The exhaust manifold pipe stud nuts need to be tightened to 32 nm (24 ft. Lbs.) and the Catalytic Converter bolts to 45 nm (33 ft. Lbs.). Lastly, reconnect heated Oxygen Sensor electrical connector, check for leak and under body contact, and lower vehicle.

Service of the three way Catalytic Converter requires a full assembly exchange with a new front flange gasket while systematic avoidance of reinstalling the original components. Rise and support the vehicle before beginning work. You need to cut power to the heated Oxygen Sensor connector followed by removing exhaust nuts from the manifold pipe while also removing the converter bolts to remove the three way Catalytic Converter. Before installation the exhaust manifold pipe gasket from Catalytic Converter front flange and heated Oxygen Sensor must be removed. To start with heated Oxygen Sensor installation follow it by putting a fresh exhaust manifold pipe gasket onto the exhaust manifold pipe studs. Start by supporting the three way Catalytic Converter before tightening the Catalytic Converter bolts. Install the bolts in order after tightening the exhaust manifold pipe stud nuts. Use at least 32 nm torque when tightening exhaust manifold pipe stud nuts while using 45 nm torque when securing Catalytic Converter bolts. After reconnecting the heated Oxygen Sensor electrical connector check for leaks and underbody contact before lowering the vehicle.

Begin the exhaust crossover pipe repair by first removing three items which start with the fuel injector sight shield and continue to the throttle body air inlet duct. First remove air pipe from the vehicle followed by heat shield nuts and crossover heat shield before extracting the heat shield itself. The exhaust crossover pipe requires removal of both its bolts and pipe while taking the seal along with it. The exhaust crossover pipe installation requires placing the exhaust crossover pipe seal onto the exhaust crossover pipe at its right exhaust manifold connection before installing the exhaust crossover pipe. Screw the crossover pipe exhaust bolts to 18 nm then tighten them by 13 ft. Lbs. Combine the exhaust crossover heat shield then fasten its nuts while applying 20 nm (15 ft. Lbs.) tension. Install the air pipe first before placing the throttle body air inlet duct and ending with the fuel injector sight shield.

Remove the two nuts at the exhaust manifold and the four nuts at the catalytic converter, then take off the exhaust downpipe.

Raise and support the vehicle.

Reinstall the exhaust crossover heat shield and secure it with the heat shield nuts, tightening them to 25 Nm (18 ft. lbs.).

Reinstall the air flow duct and the power brake booster heat shield.

Place a new exhaust crossover pipe seal into the exhaust crossover pipe.

Position the exhaust system rearward enough to allow the studs located in the front of the catalytic converter to clear the exhaust manifold pipe.

Take out the secondary air injection (AIR) feed tube.

Install the HO2S, tightening it to 42 Nm (31 ft. lbs.), connect the engine harness electrical connector to the HO2S, and reinstall the oxygen sensor wiring harness heat shield.

Use a rivet gun to fasten both the oxygen sensor wiring harness heat shield and the catalytic converter heat shield to the floor panel with a single rivet, install the remaining rivets, and finally reinstall the exhaust system.

Remove the catalytic converter gasket, ensuring not to reuse it.

Reattach the power brake booster heat shield to the exhaust crossover and secure it with the two nuts, also tightening them to 20 Nm (15 ft. lbs.).

Remove the four bolts attaching the exhaust crossover to the exhaust manifolds and take the exhaust crossover out of the engine, ensuring not to reuse the seal.

Remove the left two frame to body bolts, lower the frame with the jack stand, and then remove the fourth exhaust crossover pipe nut.

Remove the two nuts attaching the exhaust manifold pipe to the right exhaust manifold.

Place a NEW catalytic converter gasket over the catalytic converter studs and position the catalytic converter to the exhaust manifold pipe.

Reinstall the transmission fluid filler tube, raise the vehicle, and use a jack stand to raise the frame before installing the left two frame bolts.

It should be supported to prevent internal damage, with vertical movement not exceeding 6 degrees.

Install the exhaust crossover pipe bolts and studs, tightening them to 18 Nm (13 ft. lbs.).

Remove the catalytic converter from the manifold pipe and lower the exhaust system.

60 N.m (44 lb ft).

Install the bolts to secure the exhaust crossover to the exhaust manifolds, tightening them to 20 Nm (15 ft. lbs.).

Tighten the exhaust crossover pipe bolts to 20 Nm (15 ft. lbs.).

Take off the exhaust crossover heat shield nuts and the heat shield itself.

Remove the exhaust crossover pipe bolts to take off the pipe and its seal.

First, remove the air intake duct.

Remove the exhaust crossover pipe nuts and then the exhaust crossover pipe.

Reinstall the thermostat by-pass tube and the AIR pipe if equipped.

Remove the air cleaner intake duct.