My basement toilet has been backing up when I run the washing machine. Today a company came out to use a camera to go into the sewer, but said they couldn't get the camera down because the sewer has a trap (which they offered to replace for several thousand dollars).

My questions:

1. Is a sewer trap something I should consider removing and replacing with PVC? (My house was built in the late '40s).

2. A snake was stuck in the sewer, and the only way they could get to it from the toilet. Could this have possibly caused my problem?

I'm not sure whether to have the trap dug up and removed and then have the high-pressure cleanout (another close to $1K) to get the camera down.

Any advice would be appreciated. I don't know anything about sewer traps and am not sure if this is worth replacing.

You could try a product called RootX to dissolve roots or other organic matter. If organic is not the cause, you are only out about 40 bucks

Thanks.
My biggest concern is whether I should have this trap dug out and replaced with straight PVC. For several thousand dollars, I don't know if it's worth the cost if the only reason I've been given is so the camera can go down.

I have heard that in the past "whole house " traps were sometimes used. I presume that this eliminated the need to trap each appliance. Never knew anybody who had one. The question is not whether a camera can get through it, the question is whether a snake can get through it, should you have blockage. Going through the toilet is the normal way of snaking a sewer if there is no clean out hub in the main stack. Most plumber will go through the toilet even if there is a clean out in the stack. Getting the plug out of the clean out is harder than removing the toilet. I'm not sure exactly what you are saying in #2. Have you had the sewer snaked before and did the snake get stuck? What's a high-pressure clean out, some kind of clean out using water under a high pressure? If so why do you need to remove the trap. It does sound like you may have a partial blockage and if so it would be in or beyond the trap. Is the only time your toilet backing only when you use the washer?
I think you should call another sewer guy, ask if his snake will go through a trap. I'm sure a small one would but it might not be large enough to clear the blockage.

Yes, I found out yesterday that all this time (since before we bought the house) there was a snake stuck between the toilet and the clean out. That's why I'm wondering if that could have been causing the backup. The plumbers found a lot of hair and lint and I'm wondering if some of that has been stuck on it and causing the toilet to overflow when the washing machine is running.

And, yes, that's the only time the toilet backs up: when the washing machine is running.

My husband thinks we should remove the trap, but it's costly and doesn't guarantee anything would be fixed. Plus, the house is almost 70 years old; I know the old drains don't handle the high pressure/high water content from today's washing machines as well as well new pipes.

I'm thinking we should wait it out and see how it goes. But then again, I don't want this to be a frequent problem (I can deal with toilet overflow once every couple years maybe -- but not every month!).