X Reg 1.8 Petrol Loss Of Power/fuel Effeciency + Vibration

[dyerseve]

Hi All, this is my first post so please be gentle with this noob . I have had my avensis for 18 months now and on the whole it has been great.

However, recently it has developed an intermittent fault. This fault normally occurs once the engine has reached its normal running temp. but it will also happen randomly whilst driving. The problem is i experience a significant loss of power(approx 25%) and the car will start to vibrate slightly. this will continue for upto a minute and then everything will go back to normal.

Ever since this has been happening, my avg. fuel economy has decreased significantly (down about 7mpg) and i can often smell petrol from my exhaust once i have finished driving.

This whole problem started after i smacked into a curb after skiding in the snow - the impact was severe enough to break my alloy.

I have taken the car to a Nationwide Auto centre who told me that a major service would probably fix the problem as it sounded to them like the car needed new spark plugs and filters (the car was due for a service anyway). I got the service done but the problem is still there. I took the car back to the same garage and got them to look at it again and this time they are telling my it is O2 sensor.

I am hoping someone here can confirm or deny what the garage is telling me as its an expensive guessing game for me otherwise.

thanks very much in advance,

chris

[igormus]

Hi All, this is my first post so please be gentle with this noob . I have had my avensis for 18 months now and on the whole it has been great.

However, recently it has developed an intermittent fault. This fault normally occurs once the engine has reached its normal running temp. but it will also happen randomly whilst driving. The problem is i experience a significant loss of power(approx 25%) and the car will start to vibrate slightly. this will continue for upto a minute and then everything will go back to normal.

Ever since this has been happening, my avg. fuel economy has decreased significantly (down about 7mpg) and i can often smell petrol from my exhaust once i have finished driving.

This whole problem started after i smacked into a curb after skiding in the snow - the impact was severe enough to break my alloy.

I have taken the car to a Nationwide Auto centre who told me that a major service would probably fix the problem as it sounded to them like the car needed new spark plugs and filters (the car was due for a service anyway). I got the service done but the problem is still there. I took the car back to the same garage and got them to look at it again and this time they are telling my it is O2 sensor.

I am hoping someone here can confirm or deny what the garage is telling me as its an expensive guessing game for me otherwise.

thanks very much in advance,

chris

hi mate

why do not you change spark plugs + MAF cleaning ??

It must to cure this issue.

Cheers/Igor

[Jamesbelfast]

Sounds very much like the engine is misfiring on at least one cylinder probably due to an ignition fault. In this instance unburnt fuel will be entering the exhaust throwing up an O2 sensor fault. As no doubt you have already discovered the odour of petrol from the exhaust would point to that aspect. What some of these numpties can't seem to grasp is that a fault showing as this does not necessarily mean the sensor is faulty. It's only a clue as to what may be happening and is not always an absolute diagnosis. If unburnt fuel continues to enter the exhaust there is a risk of damaging the CAT which could be an expensive repair so I suggest you get the car checked out by someone who knows what to look for as soon ASAP.:)

[dyerseve]

Sounds very much like the engine is misfiring on at least one cylinder probably due to an ignition fault. In this instance unburnt fuel will be entering the exhaust throwing up an O2 sensor fault. As no doubt you have already discovered the odour of petrol from the exhaust would point to that aspect. What some of these numpties can't seem to grasp is that a fault showing as this does not necessarily mean the sensor is faulty. It's only a clue as to what may be happening and is not always an absolute diagnosis. If unburnt fuel continues to enter the exhaust there is a risk of damaging the CAT which could be an expensive repair so I suggest you get the car checked out by someone who knows what to look for as soon ASAP.:)

hi james, thanks for your detailed reply. yes it def seems to be a misfire but what is causing the misfire is the problem. i am not sure if the sensor is faulty and so the fuel/air mix is wrong or like you said, there is an ignition problem. the thing is, as i have just had all the spark plugs changed and the problem is still there, what else could it be? leads? engine management computer?

when you say i should take it to someone who knows what they are talking about - i take it you mean a toyota garage?

[dyerseve]

Hi All, this is my first post so please be gentle with this noob . I have had my avensis for 18 months now and on the whole it has been great.

However, recently it has developed an intermittent fault. This fault normally occurs once the engine has reached its normal running temp. but it will also happen randomly whilst driving. The problem is i experience a significant loss of power(approx 25%) and the car will start to vibrate slightly. this will continue for upto a minute and then everything will go back to normal.

Ever since this has been happening, my avg. fuel economy has decreased significantly (down about 7mpg) and i can often smell petrol from my exhaust once i have finished driving.

This whole problem started after i smacked into a curb after skiding in the snow - the impact was severe enough to break my alloy.

I have taken the car to a Nationwide Auto centre who told me that a major service would probably fix the problem as it sounded to them like the car needed new spark plugs and filters (the car was due for a service anyway). I got the service done but the problem is still there. I took the car back to the same garage and got them to look at it again and this time they are telling my it is O2 sensor.

I am hoping someone here can confirm or deny what the garage is telling me as its an expensive guessing game for me otherwise.

thanks very much in advance,

chris

hi mate

why do not you change spark plugs + MAF cleaning ??

It must to cure this issue.

Cheers/Igor

hi Igor, thanks for your reply. the spark plugs were change very recently during a major service and this has not solved the problem. what is MAF cleaning?

[igormus]

Hi All, this is my first post so please be gentle with this noob . I have had my avensis for 18 months now and on the whole it has been great.

However, recently it has developed an intermittent fault. This fault normally occurs once the engine has reached its normal running temp. but it will also happen randomly whilst driving. The problem is i experience a significant loss of power(approx 25%) and the car will start to vibrate slightly. this will continue for upto a minute and then everything will go back to normal.

Ever since this has been happening, my avg. fuel economy has decreased significantly (down about 7mpg) and i can often smell petrol from my exhaust once i have finished driving.

This whole problem started after i smacked into a curb after skiding in the snow - the impact was severe enough to break my alloy.

I have taken the car to a Nationwide Auto centre who told me that a major service would probably fix the problem as it sounded to them like the car needed new spark plugs and filters (the car was due for a service anyway). I got the service done but the problem is still there. I took the car back to the same garage and got them to look at it again and this time they are telling my it is O2 sensor.

I am hoping someone here can confirm or deny what the garage is telling me as its an expensive guessing game for me otherwise.

thanks very much in advance,

chris

hi mate

why do not you change spark plugs + MAF cleaning ??

It must to cure this issue.

Cheers/Igor

hi Igor, thanks for your reply. the spark plugs were change very recently during a major service and this has not solved the problem. what is MAF cleaning?

it is MASS AIR FLOW meter -- must be close to throttle or combined.

But please also check with carbon deposits in throttle as well. I ve cleaned mine before due to similar issue with engine vibration + changed all spark plugs. Cheers/Igor