If you own a 2004, 2005, 2006 or 2007 Toyota Corolla and your car hesitates when you accelerate or it hesitates when driving, you should try the solution described here. Below is a list of the behavior your car may show that tells that you should try this procedure before going to a mechanic or repair shop.
- The accelerator is slightly pressed while the car is running and it slightly jitters or hesitates
- After completely stopping the car (a red light for example), it hesitates when you accelerate to continue driving
- Engine power is below the usual level
- Sometimes check engine light turns on
You should know that while those problems can be
caused by several issues, including low quality or altered fuel or even a loosely tighten fuel cap, the most common cause is a dirty MAF flow meter sensor.
The MAF sensor (Mass Air Flow Meter Sensor) is in charge of detecting how much air (in mass, not volume) is coming in to the engine, so the ecm computer can calculate the amount of fuel to be injected.
Some times this sensor gets contaminated by lots of microscopic debris that scape the air filter and accumulate on its sensing parts over time. The resulting effect is that the MAF flow meter sensor gets less "sensible" and detects less air than it is currently entering the engine. The reaction of the ecm computer will be to inject less fuel to keep the air fuel balance, taking as reference the false reading of the MAF flow meter sensor. This will produce a too-lean mixture, which is responsible of the hesitation, the loss in power and the check engine light.
If your car engine, besides the hesitation, is also producing knocking or engine pinging at high loads, like when going up through a hill, it is attributed to this too-lean condition.
Before going to an auto parts store or to a mechanic to fix the problem, you should try fixing it your self. If the problem is a dirty MAF flow meter sensor, the solution is to clean it, plain and simple. That may save you some money that a mechanic will charge for cleaning it (you could do the same) or for replacing the part when most of the times it is not damaged, just dirty or contaminated