drove my mom's crv to the airport yesterday and on the way there after about 1 hour of driving i heard the blow by from somewhere when i was going uphill under load
then on the way back it progressively got worse and worse and car was hella sluggish by the time i got to my exit. and check engine light came on about 15 minutes before i got home
code p0131
any slight load on the engine would start blowing air from somewhere adn sound like thomas the train.
car has 197000 miles havent had any issues for almost 2 years

 

Have you checked your primary O2 sensor and associated wiring

 

why would i hear air blow by even with bad o2 sensor?

 

could be a clogged cat

 

The error code P0131 relates to the primary O2 sensor – The blowing noise could be a blocked CAT, or if you have been over rough ground you may have damaged the O2 sensor, hence my comment.

 

it was clogged cat.
does crv have common problem with clogged cats?
my wife's crv cat melted on teh back side
and this one disintegrated on teh front didnt fall apart just disintegrated like termites ate it.
and when i bang it out it was like chimney ash.
o2 sensor code went away

have to order a new cat

what would cause either case?

 

Sounds like the fuel you are using may have a very high sulphur content, check with your supplier and if this is the case you can purchase additives to counteract this problem.