2003 Subaru Forester



September, 29, 2009 AT 2:16 PM

Computer problem
2003 Subaru Forester 4 cyl All Wheel Drive Automatic 89000 miles

The check engine light came on. I took the car in for an oil change and the check engine light. The repair shop said that the code indicated that it was the catalytic converter. The catalytic converter cost $870. He said that he could clear the code for me and see if it came on again. That it would take about a week or two and that it would not hurt the car. Can you tell me if this is accurate, please? Will it do damage to the car if I continue to drive it? If the code indicates that it is the catalytic converter, does that mean it needs to be replaced? Or, could it be a sensor or something else? Any advice as to how to prodeed? Thanks in advance for you help.


3 Answers



September, 29, 2009 AT 3:25 PM

Hello -

To better assist you is your model the X, or XS? Also what is your engine size in liter?

Please go to Auto Zone (AZ) or O'Reilly's (OR) and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don't get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery and alternator.

Is the vehicle running any different at this time.



October, 26, 2009 AT 1:12 PM

Thanks for your response. The car is 2003 25 XS AWD. The mechanic said the code was PO420 (catalytic converter system). He said that it would cost about $850 to fix using NONsubaru parts. When I spoke to Subaru repairs - they said it would range from $1200-$2500. But, said that wherever I decided to get it done to make sure to use GENUINE subaru parts. The mechanic cleared the code and said that I would need to get it repaired the next time I changed the oil with him.
The check engine light has come on again. Can you please advise if any of the above is correct and do I need to do this immediately? The car seems to be running ok. Has some kind of whirring noise (seemingly on the right) on acceleration.



October, 26, 2009 AT 9:53 PM

Hello -

Thanks for the update

1. Perform basic diagnostic procedure. See BASIC DIAGNOSTIC PROCEDURE. If DTC P0420 is only DTC set, go to next step. If any DTCs other than P0420 are present, diagnose and repair those DTCs first. Do not diagnose DTC P0420.
2. Check for exhaust leaks or air suction caused by loose or missing nuts and bolts, or damage to exhaust system. Check especially between cylinder head and front exhaust pipe, between front exhaust pipe and front catalytic converter, and between front and rear catalytic converters. If damage is found, repair or replace exhaust system. If no damage is found, go to next step.
3. Separate rear catalytic converter from exhaust pipe. If there is damage at catalytic converter, replace front converter. If there is no damage to catalytic converter, go to next step.
4. Disconnect rear HO2S harness connector. Measure resistance between ECM harness connector B135, terminal No. 19 and rear HO2S harness connector terminal No. 3. See Fig. 10 and Fig. 11. If resistance is less than one ohm, go to next step. If resistance is greater than one ohm, repair open between ECM and rear HO2S harness connectors.
5. Check sealed wire. If sealed wire is not properly connected, repair sealed wire and test system operation. If sealed wire is properly connected, contact authorized Subaru dealership because probable cause is deterioration of multiple parts. Clear memory and perform verification procedure. See CLEARING DIAGNOSTIC TROUBLE CODES and VERIFICATION PROCEDURE

What I would do is definitely number 2 above. Check your exhaust system really good for leaks, air suction etc. This may be the noise you are hearing.

Make sure your O2 sensors are secure and nothing is loose on the exhaust as it says.

The cost of $850 is close. Depending on what they are replacing. May be just a tad high but again, I am not sure what all they are replacing and the area you are in.

I would get a few more estimates.I wouldn't worry about just Subaru parts for the cat.

Again, before replacing anything I would do as number 2 says above.

Let me know.

Please login or register to post a reply.

Code Read Retrieval/Clear Mercedes Benz
Code Read Retrieval/Clear Honda Civic
How to read codes Chevrolet Blazer
Code Read Retrieval/Clear Mercedes-Benz C230
How to gather codes Ford Explorer
Code Read Retrieval/Clear Scion XD
Read Codes Like a Pro