1997 Honda Accord LX; 5 door (station wagon);
F22B2 engine (4 cylinder); KA5MT (5 speed manual transmission)

I have replaced these exhaust system parts - middle pipe, B pipe, and muffler - with new Honda OEM parts as indicated on the schematics and parts list provided on the Honda estore website and by Honda dealers.

The outlet on the B pipe is 49mm outside diameter (the A pipe, middle pipe, and B pipe are all 49-50mm OD) but the pipe on the muffler is 45mm OD.

The gasket (18229-SS1-000) which came with the muffler is 45mm ID. In other words, Honda apparently intends this 45mm muffler (with the 45mm gasket) to match with a 45mm B pipe. The problem is the B pipe they indicate is 49mm.

Part numbers are as follows:
Middle pipe: 18201-SV4-A31
B pipe : 18220-SV1-C70
Muffler : 18030-SV5-506

QUESTIONS: 1.Has Honda made a mistake in indicating this muffler with 45mm pipes for this car? (Everything else is 49-50mm) 2.What is the diameter of the B pipe and the muffler supposed to be? I know the dimensions of my new parts by measuring them but I don't know what they are supposed to be. 3.If I have the right B pipe and muffler then what is the right gasket to make the transition from the 49mm B pipe to the 45mm muffler?

MY EFFORTS TO SOLVE THE PROBLEM:Since the B pipe is an SV1 part I tried an SV1 gasket (18229-SV1-003). It was a little loose on the B pipe and I had to hammer it into the recess of the muffler flange. In other words it didn't work well - I got the joint bolted together but it is too tight. The Honda dealer wants me to try gasket #18229-SV4-A71 but he is not sure of its size. The Honda Parts Analyst could not give him dimensions on any of these parts to verify that I have the right parts - that they were labeled correctly. Honda Customer Relations could not give me dimensions and would not allow me to speak in any manner with their tech support people - they referred me back to the dealer. I suggested to Honda Customer Relations that parts dimensions should be available to owners and dealers.

 

Wagon exhaust systems are weird. Last year when doing some exhaust work I kept running into seemingly contradictory part diagrams at the aftermarket web sites (AP/Walker/Borla). Searching for a solution, I ran across this and bookmarked it:

"http://www.justanswer.com/honda/1yw71-1997-honda-accord-lx-wagon-vin-1hgce1827va006780-this.html"

Page down to how he ended up solving the problem using OEM parts:Hope this helps.