So I got an estimate from a shop to replace the Cat 1 in my 07 Ford Expedition and he said it would be $1000. I called a muffler shop in town and they told me about $360 because they would weld it. I know nothing about any of it so I'm trying to find out why the huge price gap and which one is better? Is the welding option a safe and reliable one?
My car has 133000 miles.
My car has an automatic transmission.
There are two catalytic converters on the Expedition, one for each "bank" of the engine. Converter 1, corresponding to Bank No. 1 of the engine (passenger side of vehicle) has quite a bit of pipe integral with the converter and so what the muffler shop is thinking of doing is cutting out just the converter from the existing network of pipe and welding a "universal" converter back in. The universal converters retail for around $100 (of course, the shop’s cost is lower), so they are charging you roughly $260 for labor. If there is NOTHING wrong with the existing pipe, this is an acceptable, lower cost strategy assuming that the welding is done properly, that is there are ZERO exhaust gas leaks at the welds. If you opt for this, be sure you ask shop staff to run the engine and look specifically and carefully at the welded joints to be SURE there are no exhaust leaks. If there are leaks, the job is useless. Welding is acceptable if done properly but not everybody can do it properly.
The $1,000 quote, which by the way seems a little too "rounded off" to be credible (exactly, $1,000? what a coincidence?) might be based on the installation of the integral converter and associated piping. If you look on the Internet at Walker Part No. 54801 you will see the entire right side (Bank 1) converter assembly as vended for your vehicle. As you can see it is roughly $330 at retail. If they are using the entire assembly (Part No. 54801) that would imply a labor charge of $670 which is economically irrational unless they intend to assign a mechanic to work on your car for an entire week to do this one job.
You have a third option. You can get a quote from YourMechanic and get the quote based on having the whole assembly replaced (the $330 part, Walker Part No. 54801) which is a good solution because the other pipes in the right hand side converter assembly (again, see image on Internet that I referred you to) are likely to be corroded. And, with the whole assembly replaced, you do not have to worry about leaks from in-field welding. If you desire a quote, simply request converter replacement - bank 1. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.