Car feels light and heavier some day. Why ?

[katana92_uk]

Hi all. It's strange one. Don't know if it's just me or what. 

Some days my car feels very light with great throttle response and just smooth over bumps etc. 

But some days it feels like as if car is full of 10 elephants and engine working hard to pull also going over bumps etc not that smooth and throttle response also bit laggy. 

I am not sure if my car needs some thing looked at or what also when I floor it I get rotten egg kinda sulphur smell. Some say it's blocked cat. 

Any input please ? 

Many thanks. 

[Farqui]

Sticky caliper maybe? The next time it feels sluggish, carefully check the heat or each wheel/disk.

[NemesisUK]

Probably "just you" akin to feeling the car always drives better after a good clean and polish...

The sulphur smell would suggest the CATs are working but you may have an exhaust leak? Sometimes one can smell the catalysed exhaust fumes if the wind is following whilst is slow traffic.. This is usually only as the CATs heat up at the beginning of a journey.

[katana92_uk]

On 5/12/2017 at 0:34 PM, Farqui said:

Sticky caliper maybe? The next time it feels sluggish, carefully check the heat or each wheel/disk.

Good tip. thanks

[katana92_uk]

On 5/12/2017 at 0:51 PM, NemesisUK said:

Probably "just you" akin to feeling the car always drives better after a good clean and polish...

The sulphur smell would suggest the CATs are working but you may have an exhaust leak? Sometimes one can smell the catalysed exhaust fumes if the wind is following whilst is slow traffic.. This is usually only as the CATs heat up at the beginning of a journey.

thanks

[GrahamG]

Have the full techstream codes checked.

Perhaps a sensor feeding the main ecu is flakey. 

Hopefully an expert will be along soon with possible culprits but an oxygen sensor especially if you have an exhaust leak or an engine temp sensor  [different from that which feeds the dash gauge] could be playing up.

My suggestions may be way off target but it must be worthwhile reading the codes and seeing the readings live as the engine warms up.

[katana92_uk]

17 hours ago, GrahamG said:

Have the full techstream codes checked.

Perhaps a sensor feeding the main ecu is flakey. 

Hopefully an expert will be along soon with possible culprits but an oxygen sensor especially if you have an exhaust leak or an engine temp sensor  [different from that which feeds the dash gauge] could be playing up.

My suggestions may be way off target but it must be worthwhile reading the codes and seeing the readings live as the engine warms up.

thanks. Can i use any OBD2 tool to get codes or it has to be techstream ? 

[GrahamG]

To get the full benefit it is much better to have Techstream rather than a simple OBD reader.

I would certainly use my Lexus main agent and not expect them to charge too much for a diagnostic check. I would also prefer them to interpret data especially that from the engine   running and warming up as opposed to just reading out stored codes.

[Cotswold Pete]

I would wonder if the throttle body needs a clean as well, though never had the sulphur smell which does sound more like sensor issues, or maybe just a good burn up the motorway to clean the exhaust system through.

 

[katana92_uk]

please confirm if this is good enough for my LS 2004 facelift.

Many thanks

http://www.ebay.co.uk/itm/Mini-VCI-Toyota-Lexus-TIS-TechStream-OBD2-Diagnostic-Interface-Scanner-J2534-/281433277273?hash=item4186bb0359:g:L-gAAOSwfcVUDDNX

[GrahamG]

11 minutes ago, katana92_uk said:

please confirm if this is good enough for my LS 2004 facelift.

Many thanks

http://www.ebay.co.uk/itm/Mini-VCI-Toyota-Lexus-TIS-TechStream-OBD2-Diagnostic-Interface-Scanner-J2534-/281433277273?hash=item4186bb0359:g:L-gAAOSwfcVUDDNX

Please be aware this is not an official Toyota/Lexus bit of kit. There have been reports of similar interfaces being infected and doing nasty things to the car and laptop.

I bought similar and had an expert connect up an old laptop for me. His parting words were, 'you are not really going to plug that into your lovely Lexus, are you?'

Mine remains unused on a shelf.

People do use them but I am completely out of my IT depth. I have been hoping to meet such a person and pick their brains.

[katana92_uk]

wee update.

I used my friends snap on OBD diags tablet and came up with no major issues.

few codes related to ABS but thats is. 

Cleared all codes and car seems to be running much better.

now I dont know if this made difference or its just physiological thing in my heed. :)