Randomly not starting when warm
My 2007 Toyota Camry will randomly not start after it gets warm (usually
after 3-10 stop/starts). Sometimes it will struggle to start, and hitting the
accelerator will fire it up. Most of the time it fires up right away, and
*always* when it's a cold start.
Autozone suggested a bad MAF sensor based on the codes below. I
cleaned the MAF sensor twice and that seemed to help for 2 months. Then
out of the blue it wouldn't start again. I had codes the entire time.
No rough idle. No decrease in fuel consumption. Brand new crankshaft
sensor.
I have had people speculate from a failing fuel pump, camshaft sensors,
PCV valve, O2 sensors.
Throwing the following codes.
P0171
P0101
P0420
Please help
6 Answers
Hook a scanner to it and. Go to data and monitor engine load percentage. Go out on a good open road. Somewhere you can run it. Go WOT. If load percentage does not do 92% and better. Faulty mass air flow
P0420 2007 TOYOTA CAMRY - Catalyst System Efficiency Below Threshold Bank 1...Possible causes: Three way catalyst converter Bank 1, Exhaust tube, Intake air leaks, Fuel injectors may be faulty, Fuel injector leaks, Spark plugs may be faulty, Improper ignition timing, Engine Control Module (ECM)...As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first......P0101 TOYOTA - Mass Air Flow Circuit Range/Performance...Possible causes: Faulty mass air flow sensor, Intake air leaks, Dirty mass air flow sensor, Dirty mass air filter, Mass air flow sensor harness is open or shorted, Mass air flow sensor circuit poor electrical connection...Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner. Reset code and drive vehicle. If the code comes back, it may be necessary to replaced the mass air flow sensor.......P0171 TOYOTA - Air/Fuel Mixture System Lean Bank 1...Possible causes: Intake air leaks, Faulty front heated oxygen sensor, Ignition misfiring, Faulty fuel injectors, Exhaust gas leaks, Incorrect fuel pressure, Lack of fuel, Faulty Mass Air Flow (MAF) sensor, Incorrect Positive Crankcase Ventilation (PCV) hose connection...If the P0171 is combined with the P0174 code, it's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replace the air filter and clean the air flow meter. If the problem persists the front oxygen (O2) sensor may need to be replaced.
Also there is a Technical Service Bulletin on this, T -SB-0114-08. Go to this to read.... http://ww2.justanswer.com/uploads/snd27613/2008-10-22_002248_p0171.pdf
Krystal829 answered 5 years ago
I am having the exact same problem. My car is the same year and model as yours. What ended up being the problem? Was it the fuel pump? Thats what my mechanic is telling me and i want to be sure before i spemd all that money to replace it. Please respond. Thank you!
This video might help. https://www.youtube.com/watch?v=u9vsrW1GJjA
