problems after big exhaust leak

[Johnathan1111]

No I don’t have a catch can but I do have an otr ( no tune ) I put on a couple of months ago, I taped a new hole in the back after the filter to place the PCV hose, ile reset the fuel trims and see how it goes , only problem is now it only shows that bank one is running lean so I’m assuming the other codes might have been old left on the obd2, so it could be possible the after cat o2 sensor is faulty also caused by the massive exhaust leak I had on that side for so long, the car is so confused and so am I, I checked all the hoses and the Solinoid and the map ( I cleaned it while I was at it ), still a bit stumped on what it could be, if it was a fuel filter I would assume the whole car wouldn’t run right same with fuel pressure, I should check the injectors it’s been a while, they had some dodgy earthing problems with a frayed earth cable a while ago that I fixed on that same side. It looks like I’m going to have to go to an exhaust shop and check for leaks then change the 2 rear 02 sensors, can’t hurt ( can only the pocket haha) it’s about the only thing left to do after checking every nook and cranny,

 

[rognvald261]

No I don’t have a catch can but I do have an otr ( no tune ) I put on a couple of months ago, I taped a new hole in the back after the filter to place the PCV hose, ile reset the fuel trims and see how it goes , only problem is now it only shows that bank one is running lean so I’m assuming the other codes might have been old left on the obd2, so it could be possible the after cat o2 sensor is faulty also caused by the massive exhaust leak I had on that side for so long, the car is so confused and so am I, I checked all the hoses and the Solinoid and the map ( I cleaned it while I was at it ), still a bit stumped on what it could be, if it was a fuel filter I would assume the whole car wouldn’t run right same with fuel pressure, I should check the injectors it’s been a while, they had some dodgy earthing problems with a frayed earth cable a while ago that I fixed on that same side. It looks like I’m going to have to go to an exhaust shop and check for leaks then change the 2 rear 02 sensors, can’t hurt ( can only the pocket haha) it’s about the only thing left to do after checking every nook and cranny,

Aha! Found it.
Short answer is that the air coming from the back of the filter is unmetered, bypasses the MAF entirely.
It needs to tap into the stream post MAF. There are plenty of detailed explanations and arguments but bottom line it was a major problem discovered by Livernois in the US with VCM OTRs and rectified by VCM a few years back.
So it doesn’t matter the brand of CAI, unless you are tuning SD only (MAFless) you need to plumb the PCV breather post MAF but pre-TB.

 

[Johnathan1111]

okay will this cause one side to be lean though, and i have had this settup for about 2 months now with no problem and now its llike this so im not sure, would it happen like that over time or will it happen instantly, if it is im just going to get a regular intake and slap it on as long as this problem is behind me haha

 

[rognvald261]

Here’s some reading from a couple of years back.

 

[Johnathan1111]

okay thanks, i took a look over it and basically a tune would be ideal, ile get back if anything improves, thanks allot