Q: Check Engine light, code P0404.

asked by on

The Check Engine light on my car is coming on. I get a code P0404, EGR insufficient flow.

Having the engine code is a great first step to getting your Pontiac Montana running up to speed again. This engine code is reading EGR, which stands for Exhaust Gas Recirculation. The EGR’s job is to redirect a measured portion the exhaust gases back into the engine. Once back inside of the engine, the now inactive exhaust gas displaces portions of both the oxygen and the fuel located in the cylinders. This will lower cylinder temperatures, which in turn lowers NOx (oxides of nitrogen) emissions. The computer in your Pontiac carefully meters the amount of exhaust gases that are recirculated. This keeps the vehicle’s pollutant emissions lower while additionally not changing the engine’s peak performance. When the amount of exhaust gas entering the cylinder gets too high the engine will not idle, causing it to stall. This is the reading of the check engine light you are experiencing.

The EGR repairs can be as simple as removing the EGR valve, thoroughly cleaning out the EGR port and reinstalling the EGR valve to correct the code issue. However, because this repair is connected to emission issues, it is best to have this issue inspected by a certified mechanic so all safety precautions can be met.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Check Engine light, code P0404.

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: I am getting a P0171 code. It runs smooth and the fuel trim is good at idle. Under load the trim goes high.

If your fuel trims are ok at idle,but seem to climb when a load is applied to the engine the problem may be in the fuel delivery or air metering. A clogged fuel filter may disrupt the flow up fuel...

Q: Frozen non-drive wheel. Will not turn at all

You won't know until you get the brake caliper off. If it is a brake problem, the caliper will be very difficult to remove but the hub will turn freely after you get it off. That could be a parking...

Q: Low beam headlight not working on passenger's side

Hello. Most of the time this occurs when there is a connection issue at the fuse box or there is a wiring issue. I would typically follow the wiring back to the fuse box to test it there. If there...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.