Failed Emissions
 

My ’97 Boxter failed the emissions test. The computer codes indicated it was the cat converters and O2 sensors. I’ve replaced them, and the check engine light came back on about 250 miles later. The same codes came up. Anyone have any experience with this. It’s a beautiful car, but not worth beans if I cant drive it.

It's finally summer, I want to drive it... :(

What are the specific codes?
 

What are needed are the specific Pnnnn codes so the books can be looked at and suggestions given.


Also is the car completely stock? No aftermarket parts or "improved" ones? Were the O2 sensors the exact parts for the model year? Porsche parts? Bosche? Part numbers? The cats you replaced came from Porsche or from ?

in the parking lot of the station, I would unplug the battery or clear all codes. Then they hook it up, and hopefully it wil not throw codes before they test it.

That is exactly the wrong thing to do; the EPA has built a trap into the DME that leaves several critical emissions sensors “not ready” for several drive cycles after disconnecting the power. This was done on purpose to prevent any OBD II compliant car from having any codes cleared just before inspection. Do it and the car will fail, and then the codes will come back.

Why not just find out what the codes are and fix it?

I should have known that the MAN would have figured out a way to screw you.

O2 sensor emulators? would that work? They are cheap.

you replaced all four O2 sensors AND thee catalytic converter? it's possible, BTW, to have a brand new O2 sensor not work at all. i have had this happen with the Bosch units before. you can unplug the O2 sensor & test it with a meter to see if it's good.

It could be the MAF - my check engine light came on and the codes read all 4 O2 sensors...they told me, there is no fault code for the MAF - his gut tells him the MAF is what is bad, and the repair is half the O2 replacement.

Good luck.

+1 on this.

This is the exact experience I had last week after flashing my ECU back to stock (from Softronic tune) and clearing a code. 3 systems came up as not ready and they wouldnt let me test, so I'm putting some miles on it now then re-testing soon. Up until that, I didn't know that clearing it would cause it to be untestable.

As too often happens, the OP posted a question/problem then doesn't stick around to follow up or explain how they found a vacuum hose off or something like bought the wrong parts for the job or ??? If your car is throwing error codes - get it checked by a qualified dealer or mechanic before you damage something.

Just curious - what is it that you are selling/wanting to buy?