Fuel economy significantly worse after following mods

[Habu]

I have the following mods so far. Catless downpipe w/ o2 spacer (I’m aware will affect fuel economy slightly), turbo inlet and intake. I’ve read that it’s fine to run these mods on stock DME tune. However, I’ve noticed a decent drop in fuel economy now. I also will over “Overboost” at times causing the car to go into limp mode, especially when it’s cold outside given the air density differences. Here’s a code readout I read yesterday for example of some of the codes. Do y’all recommend tuning the car urgently? If so, I can run a OTS map in the meantime. I’m considering buying a license to monitor my A/F ratio to get an idea.

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[razorlab]

You can use the MG Flasher app and log the car without paying for a license, you just need to create a (free) account.

https://apps.apple.com/us/app/mg-flasher/id1492813749

 

[BMWAF]

I'm currently running a 200CEL catted down-pipe with a JB+ at 3pm (98RON) and even during spirited mountain climbs, I get consumption of around 9.5-6/100km max.

 

[Habu]

You can use the MG Flasher app and log the car without paying for a license, you just need to create a (free) account.

https://apps.apple.com/us/app/mg-flasher/id1492813749

Thanks

 

[razorlab]

Thanks

You used the 02 spacer on the second (lower sensor) 02 sensor right? Not the first one?

 

[Habu]

You used the 02 spacer on the second (lower sensor) 02 sensor right? Not the first one?

Correct, the second port on the Downpipe to simulate a “cat” & trick the Ecu.

 

[kern417]

those codes indicate the downstream o2 sensor probably needs to be replaced.

also, sometimes the o2 spacers are too long and cause issues. especially if it has an elbow. try running a shorter spacer.

 

[Habu]

those codes indicate the downstream o2 sensor probably needs to be replaced.

also, sometimes the o2 spacers are too long and cause issues. especially if it has an elbow. try running a shorter spacer.

What’s up Kern! Love the YouTube vids. This is the length of the spacer I’m using (pic scale reference) no measurements.

 

[kern417]

What’s up Kern! Love the YouTube vids. This is the length of the spacer I’m using (pic scale reference) no measurements.

nice, i wouldn't suspect that's the issue then. just swap the sensor.

also make sure the spacer is full threaded in and not causing an exhaust leak. ultimately, flashing a map eliminates the need for it, so you could just remove it with an OTS tune.

 

[Habu]

Alright ?

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