Salams to all. Wish I had found this forum earlier! Have been a vitz '99 (silver, a/t, no cng) owner for about a year and over all it's been a great experience and very good value for the money!
Except for a minor issue that started about 3 months ago. And that's what I was searching on when I found PW.COM.
So here goes...
Some times, when accelerating from dead stop (e.g. at a signal) the car wouldn't respond. It would go max to 5kmh for 2-3 seconds... during this time if I press the pedal more, the car sort of starts choking... and after 2-3 seconds everything is back to normal. Once it starts accelerating, it runs as good as anything and nobody can say there's something wrong with the car!!
Now this problem used to occur very rarely. It was more noticeable when there was some load (e.g. a/c was on, more than 2 ppl were sitting or car was on a climbing road).
During the past 3 months, since I first noticed this, the problem has slowly become more and more noticeable. Now everytime I start from a dead stop on a slightly climbing road, I see the 2-3 second lag in response. Even the choking has now become so severe that during this time the brakes become hard (maybe enough power is not being produced).
I have already changed the spark plugs and gotten the throttle body cleaned up (don't know if the mechanic did it correctly). The "engine check" light is also normal - doesn't light up after the car is started. According to the silencer guy and a mechanic, the problem is not with the cat converter either. Now I have to leave the car with the mechanic as he'll clean up the sensor (probably the O2 sensor on the air intake) and see if it solves the problem. Otherwise he says that sensor will need to be replaced.
Plus, now that I think of it, it seems the most significant degradation came after the last service/wash done. Also, there is a very minor knocking sound that has developed along with this problem. Have tried hi octane too but even that doesn't reduce the slight knocking sound.
Will appreciate the help. Thanks.