PO133 vs. PO171 Leaking Intake Manifold Gasket

Status
Not open for further replies.
Joined
Jun 6, 2013
Messages
1,600
Location
sw ohio
Greetings All-
my 04 Vibe/Toyota Matrix/Corolla 1.8 lit up CEL. Stored Code was PO133- O2 sensor (front) slow response. Toyota TSB indicated likely cause was a leaking intake manifold gasket in cold weather (common problem). My question: why code PO133 (slow O2 response) and not PO171 (lean mixture)? PO171 makes a lot more sense than a slow responding O2 sensor.

Repair is very simple and minimal cost ($3.50) for Fel-Pro Gasket.
 
I replaced that gasket on my Corolla due to a CEL. I forget the code number. It is a very simple repair.
 
I did get the PO171 about 4 years ago. The P0133 could be linked to same thing. If you never replaced the gasket, may as well replace it first and clear the code and see if it comes back. If you havent done it yet.. it wont hurt to clean the MAF airflow sensor and the throttle body if it hasnt been done in awhile. Not to say its linked to your issue.
 
Last edited:
Replace the manifold gasket and the tensioner o ring, clear the code and see if it comes back. If it does, u may need new O2 sensor
 
Thanks All-
I initially bought an O2 sensor (OE Denso) thinking since the car has 120k miles on it, the O2 sensor has got to be lazy and responding slowly and it would not hurt to replace it. The PO133 code convinced me, too. I have been aware for a long time the leaking intake gasket is a known problem but because the car ran so well (and still does), why mess with it. I guess now is the time.

Just curious about the codes..
 
Status
Not open for further replies.
Back
Top