Threeper88

I've spent the better part of the last two weekends fighting this Full Race catted downpipe on my 2018 3.5. I didn't want to post until I was sure I couldn't resolve this issues myself. So three things....

1) Both connections to turbo flanges leak at the top.

2) Driver side pipe right before Y merge collector contacts corner of transmission pan. Vibrates/noise under throttle.

3) Driver side forward 02 sensor bung location. 180* opposite factory location, wire has no slack to connector and rests on turbo flange.

Worst of these three is the leaks. The downpipe connections where the flanges meet at the turbos leak at the top. I can hover my hand above both driver and passenger side connections and start the truck and feel gasses shooting up from the top. I've had the bottom of this truck apart twice and have loosened all connections at least 10 times trying to eliminate these leaks. I've tried different tightening orders, different adjustments while tightening, jacking up sections of the downpipe while tightening to no avail. I've been able to reduce these leaks but not eliminate. I'm at a loss here. My last resort is to use Permatex exhaust sealant. I'd rather not but I think I'm out of options.

Same sort of deal with the contact before the Y. I can get myself about 1/4 - 1/2" of clearance here but as soon as I go to tighten the y pipe to resonator pipe the gap closes and I have contact. This is the case with all combinations of the stock exhaust, corsa exhaust, factory resonator pipe, and resonator delete pipe. The problem it seems is the two hangers on the driver side. Between the two of them there isn't much play and the driver side section of the down pipe pretty much sits where it's gonna sit. Not sure what to do here other than add some kind of buffer to absorb the vibration.



Lastly the 02 sensor. The bung for the first driver side 02 sensor is 180* opposite the bung on the factor downpipes. This eliminates all the slack for the wire and the wire must straight shoot up to the connector requiring it to rest on the turbo flange. Obviously this area gets extremely hot and I'm unsure of the long term survivability of this wire. No damage thus far but it can't be good. I'm not sure why they changed the bung location, doesn't make sense to me.



So, pretty disappointed with this piece especially for the price tag. Perhaps fitment has changed for the 2018. I'm contacting Full Race and I'll relay what they have to say. Anyone else experiencing similar issues?

Great welds, fitment not so much....