Hello,
I have a 2007 Toyota Matrix Base and it is stalling when shifting into drive from park during cold start. It does the usual high idle at around 1400 RPM during the cold start and it will go back to normal idle at 800 RPM after warming up. It will not stall if I shift into reverse and pause for a second and then shift into drive. After the car warms up, the problem goes away. It has been relatively colder than usual here in Florida. I have had a P0456 CEL for a while before this happened so I don't think it's related. Within the year since I bought this car, I've replaced intake manifold, engine coolant sensor, spark plugs, MAF sensor, VSV valve, cleaned throttle body, and other maintenance. This problem just started 2 days ago.
Did the original MAF sensor test bad? Did you replace it with an OEM sensor?
The P0456 code may be related if involves a vacuum leak that is getting worse.
I cleaned the old MAF sensor with contact cleaner and ruined it. I replaced it with a Denso, not Toyota one. Do you think the leak would be near the canister or near engine compartment? Thank you.
I cleaned the old MAF sensor with contact cleaner and ruined it. I replaced it with a Denso, not Toyota one. Do you think the leak would be near the canister or near engine compartment?
Denso is probably the OEM supplier to Toyota for the MAF sensor so you should be OK on that score. You're dealing with a 17-year-old car, deteriorated rubber vacuum lines could be anywhere. The intake manifold gasket should also be checked. Any unmetered air being pulled into the intake can cause a problem, especially when the engine is cold and running open loop.
There are other possible causes as well, but it's pretty easy to check for vacuum leaks.
https://www.youtube.com/watch?v=9CPqbaSgcok
Thanks for the info! Would this technique work to check around the charcoal canister? I'm inclined to think the leak is near there. I have replaced the intake manifold gasket this year. Thank you.
That technique should work for any hose or component where vacuum is being pulled by the engine.