Hi Elijah, I'm glad to assist you. Yes, these are the left and right side converters. Click on the link below for direct ordering to take advantage of our ongoing discount and limited stocks. I hope this helps, and happy shopping. https://www.carparts.com/catalytic-converter/evan-fischer/set-repb960304-2?can=CPAE1047_CSQA_20230118

It's technically "front and rear" since these fit an inline 6 engine - both catalytic converters install on the right side of the engine, front to back, 3 cylinders per manifold. "Left and right" would indicate a V6 or V8 engine, but as long as you're sure you've selected the correct vehicle, these will fit. I'll add that the fit isn't great on these Evan Fischer catalytic converters, but they did bolt on okay for me after some effort.

One technically sits in front of the other. But they are for both sides.

Hi Brendon, thank you for reaching out. Yes, a faulty converter can do that. Kindly tell us more details once you have the vehicle diagnosed. Have a good one!

You will get a PO430 or PO341 error for that (read with OBD) , but in my case There were more obvious earlier signs. 1.) Runs great for 1 minute after a cold start (from the firce way) then doggy after that (becuase the platinum bee hive breaks off and falls to bottom .. restricting air flow). The best test for a 325 series? Remove the O2 sensors from bank 1 and 2 and drive a few miles with them out (don't unplug them though). If the far runs great again .. its your Cats. (PS you need the OBD to reset the fault light after the test). Its worth 75.00 to have a shop run a bore scope camera into your cats.. They can tell in a second if its clogged.

The cats are ok, but everything else that comes with it is junk. Ie bolts way too short, gasket is as flimsy as a potato chip, my mechanic wouldn’t put it on, there were a few other things I can’t remember. It took away my CEL, but it came on again, I suspect it’s bc of the high mileage on my car 240k. Expect to pay an extra $100-$150. But all in all it’s better than paying $1700 to bmw just for parts. I sold mine for $550, so I just about broke even. Good luck.

Yes it can cause a check engine light. But May not be successful in making the light stay off. I’ve been unsuccessful in keeping the light off after installing this converter. BMW is an engineering piece of garbage

Hi Fidel, I'm glad to assist you. Yes, they will. Click on the link below for direct ordering to take advantage of our ongoing discount and limited stocks. I hope this helps, and happy shopping. https://www.carparts.com/catalytic-converter/evan-fischer/set-repb960304-2?can=CPAE1047_CSQA_20230117

Hi. Not sure about firmest on yours, but the major parts of mine fit. The gasket is a piece of REALLY flimsy plastic that just snaps in half, so get the oem one. Also, the bolts were the wrong size for my engine, so I had to end up buying them OEM from dealer also. As far as the cats go, they work fine and pass emissions in PA, keep in mind I had to buy other parts to make it work, but no more failing emissions. The other thing I did notice is that they are slightly throatier which is fine by me bc I use it as a more utility vehicle. All and all I’d say pretty good deal even with the extra $200 for the stuff I told you about. Cheers!! And do NOT put that gasket on your car.

Hi Matty, I'm glad to assist you. No, they won't. Click on the link below for the catalytic converters we have available for the 2006 530i models. I hope this helps, and happy shopping. https://www.carparts.com/search?q=Catalytic_Converter&vehicle[year]=2006&vehicle[make]=BMW&vehicle[model]=530i&vehicle[submodel]=Base&vehicle[cylinders]=6&vehicle[liter]=3%2E0&filters[universal]=false

No it Won’t work

Hi James, thank you for reaching out. No, it will not. Click this link to order the suggested catalytic converter for the 1999 BMW Z3: https://www.carparts.com/search?q=Catalytic_Converter&vehicle[year]=1999&vehicle[make]=BMW&vehicle[model]=Z3&filters[universal]=false&can=CPAP3648_CSQA_20220926 I hope this helps. Happy shopping.

No it will not