Troubleshooting

Use fault codes, soot, DPF, NOx, and SCR symptoms to separate a DEF issue from diesel exhaust system problems before replacing parts.

Smoke testers fit most exhaust leaks; combustion block-test kits fit suspected head-gasket or cooling-system faults. Compare kit types, prices, and key features.

AUTOOL SDT206 is the strongest all-around pick for DIY exhaust leak diagnosis, with low-pressure control, a gauge, a flow meter, and dual air modes.

Choose stainless steel for salt, winter roads, short trips, or long service intervals. Aluminized systems cut upfront cost but usually need earlier replacement.

Use chrome or polished stainless tips for most show-correct classic cars. Includes a table of styles, diameters, exit lengths, and era cues.

Slash-cut tips suit most Harley Touring and Softail buyers. The guide compares outlet size, mounting method, and bag clearance.

Single exhaust fits most stock and towing diesel trucks; dual exhaust makes sense mainly for high-horsepower builds, extreme heat control, or a look-first build.

Use 4-inch exhaust for most diesel trucks; keep 3 to 3.5 inches for stock or towing setups.

Expect $20-$60 for a temporary patch, $80-$250 for a weld repair, and $150-$600 for a muffler replacement, plus what raises the price.

Round straight-cut tips usually give the cleanest soot pattern and simplest fit for diesel trucks, with slash-cut as the next-best style option.