Check Engine Light on 98 Honda Accord DX

[AGerber]

Hello everyone,
My husband has a 1998 Honda Accord DX with 193,500 miles on it. He mostly did routine oil changes, but he didn't maintain the car as well as he should have. He's an astronomer, so he drove the car up/down from an observatory at a 5,000 ft. mountain on a weekly basis, and wore down the brakes pretty fast... the car has been used pretty heavily (aka: he hasn't been kind to it).

The "check engine" light just came on and he took it into the shop to get "diagnosed." They said his catalytic converter is bad/needs replacement, and the oxygen sensors need replacement. They quoted him $700 for catalytic converter, plus $100-200 per oxygen sensor.. He recently just put $900 of repairs into the car, and we Kelley Blue Booked it, and it's only worth around $1250-1400 at this point, if we sold it privately. $500 trade-in value at a dealership.... the big question is, what should we do? Should we try to sell it NOW, while it will still pass emissions inspection and sell it "as is," or should he continue to drive it until it dies, and then trade it in for practically nothing? He has already put a lot of money into the car, and he was hoping it would go to at least 200-250k, but it's turning out to be a major money pit. We are a young, recently married couple, and we are trying to save money......

Any suggestions would be greatly appreciated. I read that he could order a new catalytic converter and have it installed at a muffler place for less.. is this an option? I also read that he could turn off the "check engine" light, but then would it just come back on anyway???

Thanks!

[shorod]

The first thing I would suggest doing is getting the exact diagnostic codes that are stored. There is no code that will say the converter is bad and oxygen sensors are bad, only codes that indicate systems which are reporting values outside of limits. If the converter and oxygen sensors were truly bad, the check engine light should have been flashing rather than just turning on and staying on. Get the actually codes numbers and post them here or research the meaning of the codes to make a more educated choice on path forward.

With a trade in value of $500 you could also contact a local automotive recycler (aka "junk yard") to see what the scrap value is. It is probably worth around $200 in scrap value, in which case driving it until it dies may not be such a bad option as long as it's still safe to drive (brakes are fully functional, engine doesn't randomly stall, steering and suspension is tight).

You could order a new catalytic converter and have a shop install it, but you'll want to call ahead and make sure the shop will install customer-provided parts. Some will, others won't. But I'd still suggest understanding what the diagnostic codes are trying to tell you before spending that kind of money. You could find the issue is just a bad vacuum line, dirty air filter, worn spark plugs/wires, or restricted fuel filter.

-Rod

[AGerber]

Code: P0420 below threshold.

[Crvett69]

i would replace the rear O2 sensor first. its often the cause of the code. or if you have a exhaust leak between it and engine. use a direct fit O2 not a universal one and a name brand not a generic one

[AGerber]

Crvett, how much does that usually cost? So, you're saying to do that first and see if the light goes off?? There were 2 codes, but the other one was a typo, apparently. Not sure what the one is for bad O2 sensors... that's just what the shop said.

My husband's goal is to spend as little money as possible, and either try to sell the car, or drive it until it dies. Everything else is working fine on the car: it's had a new transmission, new hoses, radiator repair (it was cracked)...

[Crvett69]

sensors usually run $50-100 for the part. if your handy with tools and get the O2 wrench you could change it yourself but light will need to be reset after its changed, most parts stores will do that for free

[AGerber]

I read that sometimes, you can replace the o2 sensor and it will solve the problem, but other times, you need to replace the catalytic converter. If this is the case, should he just sell the car "as is" and let people know that it needs replacing, or just drive it until it dies? The catalytic converter replacement cost was quoted at $700 (not including labor, I think...).

[Crvett69]

sounds like either way the O2 needs replacing and its the cheapest part. also you can get a new bolt on cat on e-bay for under $150 and just have someone bolt it on if the O2 doesn't fix it

[vgames33]

Those codes are not a "drive it till it dies" kind of condition. The car won't pass emissions as is, but it will run just fine.

Just going by the codes, I would start with the rear O2. The usually only require a little muscle and a 7/8 wrench to swap out. Rockauto is usually the cheapest place to get parts.

It may be time for some service, but if the car is in good shape its probably worth fixing. Can you replace your car for 1000 bucks?

[AGerber]

vgames, our situation is that I currently drive a newer Honda Civic, which I would give to him, and he would get rid of his.. .yes, his car runs pretty well, but like I said, he didn't maintain it as well as he should have, so it's bound to continue to have problems.

Also, he has already put well over $1,000 of repairs into it in the last year. More like $2,000.. he has already put more than the car is worthof repairs into it.

He's going to try replacing the O2 sensors first, and see if that helps. He's concerned that no one would want to buy the car if it won't pass emissions testing.

[AGerber]

Update: My husband replaced 2 of the oxygen sensors, and the "check engine" light is STILL on.... does this mean that he should replace all of them, or that it's the catalytic converter that is actually failing?

He did the free diagnostic at the shop, but he hasn't done the detailed one that costs $80... what would ya'll recommend? He really wants to sell the car, but we are afraid no one will want to buy it with the light still on.

[Crvett69]

what ones did he replace? the ones closest to the engine or the ones behind the convertors. ones behind the convertor are the ones that usually set the light. might be 1 or 2 depending on the exhaust setup. also did he get the light turned off or just the codes read. need to get the light turned off after doing repairs then see if it comes back on

[vgames33]

The code has to be cleared after the sensors are replaced.