Dorman 674-703: Front Catalytic Converter with Exhaust Manifold for Chevy/GMC/Hummer Models - Non-CARB Compliant Review

Very satisfied with this product. Everything was there for the exchange. I saved 600.00 by ordering and installing with help.

Much stronger than OEM. This one is welded all around, not just spot welded like the original. GM should have a review and deliver it.

I have used Dorman products for many years. You are a great company. It comes with original GM manifold gasket and downpipe bolts. You can't ask for much more.

Wrong size or to fit advertised vehicle. The original part number is not original, the machined bolt holes connecting it to the engine do not match any of the engine's manifold bolt holes.

The manifold fits well, the mating face needed grinding to ensure tightness and leaks. The supplied seal is not recommended, just cleaned the original steel seal and it worked great. The upper heat shield fits snugly, but there is no mount for the lower heat shield to protect the lower control arm bushing. (very close) Used two steel clamps and all is well. The part fit well and has worked great so far.

The previous comments on this manifold with clearance issues on the Hummer h3s are correct. I had to spend 3 hours grinding the gearbox housing to get the manifold to fit properly. Totally pissed about it. I have always used Dorman products and this was the first time I had any issues with this brand. The manifold also came with a random exhaust manifold gasket for the 4 cylinder engine and not the correct one for the 3.5 5 cylinder engine. I would choose a different brand if you don't want to…

This distributor has a design flaw. The post-catalyst knee is too big and hits the Chevy Colorado 05 engine block before the flanges are upside down, resulting in a massive exhaust leak from all cylinders. Dorman is aware of this issue and has called back. I checked this distributor against the same part number at a local parts depot and they had to pull it out of the "Dorman Recall Parts Bin" before they could show it to me. I'm not sure how anyone got this part to work. DO NOT purchase until…

So nothing against Revain, they were great! The product was delivered on time. Both times. The manifold was fine too, good quality and very good welds around the converter body, it fitted perfectly and the heat shield and anything else attached to the manifold bolted on with no problems. HOWEVER, Dorman has a problem with the packaging department. The first box came with no installation kit, which is a bag of screws and studs and a donut ring to connect the intermediate pipe. Also, the manifold