Q: My car doesn't pass emissions because the catalyst system is below threshold, and the exhaust gas recirculalation is insufficient.

asked by on December 23, 2016

The fail codes are: P0402 Catalyst System efficiency below threshold (bank 1) and P0401 Exhaust Gas Recirculation flow insufficient.

I had what I believe was a minor misfire about 3 years ago, because the check engine light did the blink on and off thing for a day or two, but that went away. It has passed emissions each year in the interim if I got an engine flush prior to doing emissions testing, but that didn't work this year.

I'm wondering what price range I'm looking at for the repairs requisite to get it up to snuff for emissions testing, and whether it's worth bothering at this point with a car at 230,000 miles.

Thanks!

My car has 230000 miles.
My car has a manual transmission.

Hi there. The Engine Gas Recirculation (EGR) valve could be sticking or full of deposits from the exhaust system. Remove and clean the EGR valve before replacing it to see if the system will begin to operate. The oxygen sensors that measure the catalytic converter is picking up an uneven measure. This says that the catalytic converter is below threshold, but if the system is too lean, the same code will come up. Simply fixing the EGR valve will fix the emissions and should make the engine light go out. I recommend driving the vehicle for a week after the light goes out before heading to the emission station.

Billing question sent to CS for the cost of fixing the vehicle to pass emissions.

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