V8 DISCO EXHAUST & CAT

[redarmytyke]

Just had new cat fitted to my disco - the old one was fried at one side and okay at the other (of the Y piece) - could this happen to the new one? if so what should I be looking for to prevent it?

Also, it runs on gas - how does this affect the cat?

also, also, running a bit lumpy when warm with new exhaust - will engine need 're-tuning'??

 

[joey]

Year... Mileage ... maintenance history would help, but my best guess is you have a bad O2 sensor or you have an injector going bad causing too much fuel to pass through the Cat which is what killed it.

Lumpy? please explain in slightly less technical terms

 

[redarmytyke]

Lumpy!!

Thanks - lumpy...here goes, idoling at around 500 rpm with rev needle dipping & raising +/- 100 rpm - ie not as smooth as when cold & idoling at 700 rpm??

rekon its worth a tank full of de-tox to clean the injectors??

Also - how much hassle/cost is changing the O2 sensor??

thanks

 

[redarmytyke]

sorry forgot - year is a 99 300 series - 53k & regular service - only basic though, no major services.

 

[joey]

Sounds more like the Stepper motor needs cleaned or changed. Do a search on here and you can find pics.

At 53k you shouldn't have lost a Cat unless something hit it hard. Personally I use Seafoam to clean out the intake/injectors about once every 6 months, then I use Lucas upper end lube once a month.