The following TSB from Volvo doesn’t mention catalytic converter failure anywhere, however the related subject matter is VERY pertinent to both false catalyst codes and real catalyst damage.
The Electronic Throttle Module (ETM) problems can be a source of unmetered (or improperly metered) air entry which is a major cause of recurring, false catalytic converter codes. Furthermore, depending upon how the lean condition manifests itself, another danger is unequal fuel distribution which will cause an overall rich condition. This will certainly lead to converter failure. The crankcase ventilation problems can cause oil blow by and other problems which will quickly cause converter damage.
NO: 25-149-D DATE: 2-20-2006 MODEL/YEAR: C70 1999-2002 S70 1999-2000 S60 2001-2002 V70 1999-2002 V70XC 1999-2001 S80 1999-2001 SUBJECT: Cleaning the Crankcase Ventilation and Electronic Throttle Module (ETM) REFERENCE: VIDA TNN 25-149-A TNN 25-149-B This TNN supersedes the previous TNN 25-149-D dated 12-06-2005. Please update your files. DESCRIPTION:
This TNN describes the method for cleaning the Crankcase Ventilation and Electronic Throttle Module (ETM). Cleaning must always be preceded by fault-tracing according to VIDA and TNN 25-149-A.
Remove: the battery negative lead from the battery the auxiliaries belt. Use wrench 999 7109 the cold air inlet hose to the control module oil dipstick pipe.
Removing the power steering pump Remove the power steering pump's three mounting screws through the pulley hole. Remove the connector with holder from the power steering pump.
Remove power steering hoses and coolant hoses from their holders/clips). Remove the tie strap for the power steering hose by the suspension turret. the coolant expansion tank and the power steering reservoir from the mounting on the spring strut turret the connector and place the reservoirs on the engine. Place the power steering pump up on the engine.
Removing the alternator
the upper screw for the alternator the screws common to the alternator and compressor. Loosen the lower screws for the compressor (so that there is some clearance). Position the alternator so that it rests against the radiator and on the air conditioning (A/C) compressor. Loosen the hose clamp for the charge air pipe on the electronic throttle module (ETM). Remove the charge air pipe from the electronic throttle module (ETM).
Remove: the air duct for the air cleaner (ACL) housing. the four screws holding the engine cooling fan's shroud. Move the shroud to one side, pull up the relay holder and pull the connectors for the fan apart. Remove:
the charge air hose from the charge air cooler (CAC) hoses and wiring from their holders both engine cooling fan relay's from the fan shroud by bending the relays inwards towards the engine compartment and pulling upwards. Open the tie strap for the wiring.
Remove: the connectors with holder on both sides of the fan shroud the canister purge (CP) valve from the fan shroud fan with shroud.
Remove the 4 x screws for the electronic throttle module (ETM). Cleaning the electronic throttle module (ETM)
Raise the electronic throttle module (ETM) and place it between the radiator and the intake manifold. Place paper under the electronic throttle module (ETM). Clean the throttle and bore as follows. Note! Do not use compressed air when cleaning the electronic throttle module (ETM). Cleaning the ETM
Warning! DO NOT submerge throttle unit in cleaning solvent. ONLY use cleaning solvent recommended in this TNN. Important! Do not scrape or use a rotary wire brush to clean the unit.
Clean the ETM bore using cleaner (P/N 11 61 828) and a soft bristle brush. Ensure that all the residue is removed from the shaded surfaces shown in the illustration. Carefully wipe the inside of the bore clean on both sides of the throttle disc. Wipe clean the edge of the throttle disc. Do not use compressed air to dry the throttle module.
Installing the electronic throttle module (ETM) Install: the electronic throttle module (ETM) with a new gasket the 4 x screws flush against mating surface.
Cleaning the crankcase ventilation Remove the banjo bolt from the intake manifold. Remove the hose (1) from the banjo nipple. Remove the oil filler cap. Blow the hose clean (1) using compressed air (2) to verify that the system is open. If the hose is blocked clean the hose using 2.0 mm diameter wire.
If air travels through to the oil filler the breather is good, no further verification or repairs are necessary. Note! If the hose is blocked, use a welding rod (maximum diameter 2.0 mm, approximately 250 mm long) to unblock the hose. Clean the banjo nipple using a diameter 2.0 mm drill bit (3).
Install: the hose on the banjo nipple the banjo bolt with new gaskets the oil filler cap.
Raise the car. Remove the splashguard under the engine Tighten the banjo bolt. Tighten to 24 Nm. Tighten the 4 x screws for the electronic throttle module (ETM). Tighten to 10 Nm.
Install the cover under the engine. Lower the car. Installing the alternator
Install: the alternator in the correct position the upper screw but do not tighten both the screws common to the alternator and the air condition (A/C) compressor. Do not tighten.
Tighten: the upper screw. Tighten to 24 Nm the lower screws for the air conditioning (A/C) compressor. Tighten to 24 Nm the screws common to the alternator and the air conditioning (A/C) compressor. Tighten to 24 Nm.
fan shroud with its 4 x screws the holder for the connector before installing the lower screw on the fan shroud's (car's) left side. Tighten both the lower screws. Thread the 2 x uppermost screws the fan connectors the engine cooling fan's relay in the holder the canister purge (CP) valve to the fan shroud the connector with holder, fan shroud's right side the tie strap around the wiring hoses and wiring in their holders/clips the charge air hose to the charge air cooler (CAC) the relay holder. Tighten the upper screws.
Installing the charge air pipe Install the charge air pipe to the electronic throttle module (ETM)
Tighten the hose clamp for the charge air pipe on the electronic throttle module (ETM). Installing the power steering pump
Install: the power steering pump the three screws. Tighten to 24 Nm the expansion tank and the power steering reservoir in the mounting on the spring strut turret the tie strap around the power steering hose by the suspension turret power steering hose and in the holder on the belt protection on the power steering pump the connector with holder on the power steering pump the coolant hose to the holder on the control module box the holder with coolant hose to the power steering hose
Install: the auxiliaries belt. Use wrench 999 7109 the oil dipstick pipe the cold air inlet hose to the control module the air duct for the air cleaner (ACL) housing.
Turn the ignition key to position 2 Install the battery negative lead to the battery. Note! The method applies to only cleaning the throttle module for the S70 1999-2000 S60 2001-2002 V70 1999-2002 5-cyl Non-turbo
Remove: the battery negative lead from the battery. When removing and installing the battery leads. See: Electrical system Battery replacement