The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

Do I need a new catalytic converter? Need help. 700 1991

posted by  john740 on  Sun Sep 21 14:48 CST 2003
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Thu Jun 28 13:48 CST 2007
[RELATED]

I have a 91 Volvo 740, failed the VET test. Readings were as follows:
HC 0.97 GPM
CO 10.10 GPM
NOx 4.06 GPM
CO2 323.50 GPM

Replaced plugs (Bosch platinum gapped at .028), air filter, rotor cap, rotor button, new plug wires (Bosch), cleaned spark arrester, oil trap, changed oil, cleaned throttle body. Put 2 bottles of STP Total Fuel Cleaner in tank and ran it through engine, mostly expressway miles. Went back to VET…failed again. Readings are as follows:
HC 1.19 GPM
CO 9.70 GPM
NOx 3.55 GPM
CO2 313.90 GPM

In both tests, readings were within limits at idle, when cruising, and when decelerating. All high readings were during acceleration. I believe that I need a new catalytic converter or perhaps a new O2 sensor. The catalytic converter is a replacement, not OEM. Has about 100K on it. I think that the O2 sensor is original. What’s the consensus? All advice sincerely appreciated.





USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.