The Plan of Attack!

[SanDiegoYota]

Hey Nation, I posted awhile back and got a lot of good feedback and I am looking to get the same today so I am here to post my Read out codes from a recent check engine light scan. I am working on a budget of $300 dollars on parts and would like to pinch every penny. So my question for you Toyota Nation... What would be your plan of attack. What should be replaced first, how could i trouble shoot this EGR problem. Here are the codes, any feedback is much appreciated! Thanks!


p0128
p0401
p0440
po446

[BMR]

P0128 - Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
P0401 -Insufficient EGR Flow
P0440 -Evaporative Emission Control System Malfunction
P0446 -Evaporative Emission Control System Vent Control Circuit Malfunction

The P0128 is most likely due to a bad thermostat. Replacing it should cost $20 - $30. Use a Toyota OEM thermostat or Stant with the jiggle valve.

PO440 could be the gas cap isn't sealing.

There are DIY threads addressing some of the others, but you didn't say if your car has a V6 or 4 cylinder. So look thru this list of stickied threads to see if they're covered.

[SanDiegoYota]

It is a 4cyl 2.2l

[SRR]

Originally Posted by SanDiegoYota

It is a 4cyl 2.2l

I'm in San Diego also and could help. Shoot me a PM. What year is your car?

[JohnGD]

As mentioned above the thermostat is probably stuck open, but also first check the engine coolant temperature sensor (2-wire sensor on the outlet pipe if for I4). Make sure the sensor responds in range. See chart:
1 or 2 Coolant Temp Sensors

You can check rockauto.com for prices as well. If I4 you can use STANT 48278 180° w/Jiggle Pin OE Type Thermostat incl gasket $10.94; V6 you can use STANT 48128 180° w/Jiggle Pin OE Type Thermostat incl gasket $15.34. (Double check applications).

Besides the gas cap, check the VSV (vacuum switching valve) that's on the carbon canister. That thing likes to stick. Also check the vacuum hoses there and elsewhere in the EVAP system for leaks.

There is a VSV for the EGR system, same problem there. And some cleaning may be needed for the valve and pipes and the throttle body ports for the modulator.

You may be able to clean the VSV by carefully prying off the metal tabs holding the tube caps, but if they break then it's a new VSV. If you don't have to replace anything (if cleaning works), then it shouldn't cost you more than some throttle body cleaner and supplies.

[xpeed]

For the Insufficient air flow on your EGR code, you could use a hand-held vacuum pressure pump and check all the hoses on the EGR and EGR module to see which one doesn't give out enough air. The EGR module should actually retain pressure when you pump air in. If the pressure escapes out right away, then the module is bad. That's about $80 for an OEM Toyota at the dealers.