wes27hoya

2003 C230 Kompressor Coupe

I need a smog check for my registration (California) but my check engine light is on, so I bring it to a local mechanic. I have the P0172, fuel too rich code. $1,600 of repairs later, the damn light is still on.

He noticed an oil leak on the solenoids first and so we've been addressing that also.

So far, he has replaced or fixed the following, per my invoices:

Invoice #1:

spark plugs
thermostat/cooling system bleeding
vacuum lines inspection and replacement
camshaft solenoid seal replacement
ignition coil cylinder #4
thermostat coolant
thermostat housing
upper radiator hose
refrigerant fluid
cleaned the harness and all connections, checked mass airflow sensor

Total: $772.22 ($450 labor)

I bought a new (used) engine harness myself because he thought that was the problem because of the solenoid oil leak traveling through it and contaminating - Ebay ~$125

Invoice #2

Labor on replacing the harness: $450

engine crankcase breather hose kit
camshaft adjuster magnet (replace both)
4 intake manifold gaskets
checked oxygen sensor and replaced it too, but it made no difference.

Invoice total: $741.75

So after all of that money, the damn code is still there. I'm at my wit's end. He says I can get a smog referee to give me a 2 year exemption but then I'd have to ditch the car in two years. Can anyone help shed some light on what it might be? He says he's checked all of the usual suspects.

He suspects the oil may have traveled though the harness and even beyond to the computer, which would have to be replaced by the dealer>

His next guess would be to replace the fuel injectors but I don't want him to keep replacing things at this point, since nothing has worked.

Thanks!

tjts1

First, find a competent mechanic, you've been taken for a ride. Maybe an MB indie who has experience with your engine. My guess would be bad MAF sensor or fuel pressure regulator but you really need a competent mechanic to take a look at it.

wes27hoya

I just remembered the dealer had done a fix on the leaking solenoid issue. I should have just brought it back to them to complain. I'd probably have more money in my wallet today.

Former post on that: https://mbworld.org/forums/c-class-w...vers-park.html

wes27hoya

What makes you say I've been taken for a ride? I do feel like that but I'm not experienced with cars so I'd like to know. Shouldn't the mechanic have seen/noticed the "pigtail"" repair the dealer did (talked about in other post I linked to)? SHouldn't the dealer have done the pigtail so my harness didn't have any oil on it?

Should I just take it to MBZ instead at this point?

C230 Sport Coup

What do any of those repairs have to do with fuel trim?
spark plugs - Shoulda coulda done that yourself! $35.
thermostat/cooling system bleeding ? no
vacuum lines inspection and replacement? yes
camshaft solenoid seal replacement- no
ignition coil cylinder #4- no but if you're getting misfires...won't cause too rich
thermostat coolant- no
thermostat housing- Really? Seriously? I don't believe it, show me the old part!
upper radiator hose- wtf?
refrigerant fluid- LOL!
cleaned the harness and all connections, checked mass airflow sensor - Checked MAF? How, did he clean it? how old is it?
engine crankcase breather hose kit- Uh yeah, maybe if it's leaking
camshaft adjuster magnet (replace both)- coulda been done fo free at the dealer.
4 intake manifold gaskets- Huh? 4? Uh...too much air = too LEAN !
checked oxygen sensor and replaced it too, but it made no difference.?

I don't see the MAF being replaced....
My guess is MAF but you need to get the codes read with
Mercedes Star Diag.

tjts1

Because you spent $1600 and the damn light is still on. Some of us spend less than $1600 buying a whole W203 and it passes smog. You need a better mechanic. I'm not saying you should DIY, its not for everyone. But for that kind of money the problem should've been fixed by now. It sounds like your mechanic is just throwing parts at the car hoping something works. He's incompetent and you're paying for it.

wes27hoya

Thank you both. I do feel dumb based on your replies but I don't know much about cars, so am looking for help. I pressed him hard on the MAF and he swore that he cleaned it (I think it's original?) and that he tested it rigorously and it shows no issue.

A lot of what he did kept coming up as he worked, eg. once he replaced the engine harness, he found those intake manifold gaskets and hoses looked like they'd need replacing so might ans well do it while he's under there now. I took his advice.

I've got a more skilled mechanic I trust. He's just 45 min away, but at this point, I think I'll take it to him.

Any other ideas in case it's not the MAF, considering how adamant he was? Could this guy be right and the oil crept into the ECM itself, which would need replacing at the dealer for >$2k?

insame1

Sometimes paying the dealer for a inspection is worth every penny.