Milltek decat

[Jamesh87]

Hi, just purchased a milltek decat downpipe to match upto my existent milltek catback from awsomegti, im planning to get it mapped next friday 16th at amd tuning, just wondered if its ok to run around with the decat fitted without a map for a week or so ?

 

[aqibi2000]

Yep fine

 

[prt57]

You will probably get a light on the dashboard which you can ignore.

 

[Whodafunk]

Yes, absolutely fine but you will more than likely get a P code fault for cat below efficiency or similar

 

[Jamesh87]

Thanks for reply guys

 

[Jamesh87]

Just received it and going to fit tomorrow.. do i still plug the sensors in as i see in the box it has two blanking plugs and 3 holes on the pipe for sensors

 

[Whodafunk]

Just received it and going to fit tomorrow.. do i still plug the sensors in as i see in the box it has two blanking plugs and 3 holes on the pipe for sensors

I'm not with you. Assuming it's not a V engine it should have space for 2 oxygen sensors, one upstream and one downstream. You could space out the downstream sensor to try and fool the car into thinking it still has a cat, but with a decat I'm not sure this will work. You're getting it remapped anyway so it shouldn't be an issue

 

[Jamesh87]

Opened box and on the pipe im pretty sure it has 3 holes and in the packaging with the washers and hanger etc it had two blanking plugs.. i thought my original only had two sensors

 

[Jamesh87]

Sorry im probery not explaing well
Picture below is what pipe i have being fitted tomorrow which ive circled 3 holes i presume for sensors? On my standard cat i have on at the moment i thought there was only two sensors.. so do i still plug those two in and just blank off one of the 3 holes on the new pipe

 

[prt57]

There are 3 holes in my APR downpipe. One of the holes was plugged and the sensors were attached to the remaining holes either side of the cat.
Just plug your sensors into the holes nearest the oem locations.
When you have it mapped ask the chap if your locations are OK. If not then they can be adjusted there and then.

 

[Whodafunk]

If the option is there to blank one I'd blank the middle one. Use the holes furthest apart for the o2 sensors otherwise they'll be reading exactly the same data (which they will pretty much do anyway without a cat). Without a remap though this setup will certainly trigger P0420/p0430 cat below efficiency. Some people use a spacer on the rear o2 sensor (the one at the right on your pic) to try and fool the ECU. This doesn't always work and people then have to experiment with different amounts of wire wool inside the spacers to filter out the gases. This is the cheaper DIY approach, whereas the remap essentially deletes the route for these specific P codes so they don't register.

 

[Jamesh87]

Perfect thanks for reply guys! I shall blank middle one and plug sensors each side then await my map on the 16th it wont go into limp mode or anyrhing?

 

[Whodafunk]

Perfect thanks for reply guys! I shall blank middle one and plug sensors each side then await my map on the 16th it wont go into limp mode or anyrhing?

No, and it should in effect run perfectly bar the fault code