Lexus is250 vcs light on

[gadslon]

Hi coming back from shoping today and 5min in got vcs warning with em and tc lights. Now i know I have to replace exhaust( couple months ago lexus did safety check while replacing passa air bag) so anyone knows will I have to replace o2 sensors and ecu or just exhaust will solve this problem. Ps shots from obdII

Thanx

[Texas]

A defective ( as in holed) exhaust will allow air in and upset the readings of the O2 sensors. So if you know exhaust is suspect then there might not be anything wrong with sensors themselves or anything else!  Then mention of LEAN in fault code insinuates too much fresh air. Firstly address exhaust problem and reset ecu ( disconnect Battery earth connection for 10 mins) or if that’s your OBD reader happy days👍

[gadslon]

Oh OK I changed exhaust and the fault still comes on after 30 minutes drive, also car seems developed some sort of problem. Acceleration is sluggish, what I mean when I accelerate hard the rev counter bounces between 2000rpm and 2100 for couple seconds than 2100rpm and 2200 and so on until gear changes and so on on EVERY gear. And I can feel it ! Also for some reason car doesn't show on dash exact gears. What I meant is when I'm in 6th gear and car reduces to 5 on hill (I can feel it and see it on rev counter) dash still shows 6th gear. Any idea what's going on? 

[Linas.P]

This being bank 1 sensor 1, I doubt air would be getting any effect. Sensor 1 is in engine bay before the cat, so unless you have leak on headers this won't be an issue. So I would say it is sensor - you can as well check sensor with standard multimeter:

[gadslon]

Thanx a lot that solved the problem

 

[Linas.P]

Welcome!