"Check Engine lamp" after cat remove - 986 Forum

x-itingcars · 04-07-2013, 01:18 PM

Hi!
I have removed the catalytic converters and installed cat bak pipes, Headers and sport exhaust from M2 Performance. It runs fine with awesome sound and good fitting. I have run for about 200 km now. And yesterday the "Check engine light" flasches up sometimes. And the engine goes on 4-5-cyl. Have anyone here. some experience of this problem?
My Car is a Boxster S -00
Best regards Jocke from Sweden

shadrach74 · 04-07-2013, 01:26 PM

Please have the code[s] read, it will make all the difference in diagnosing your problem...without that information, any answer would be a guess.

Johnny Danger · 04-07-2013, 02:17 PM

Correct me if I'm wrong, but RoW boxsters don't have pre-cats. Right ?

mikefocke · 04-08-2013, 08:36 AM

The simple answer is to ask you what codes are read out of the OBD2 port by a scanner.

Are they connected either to emissions or engine control or something else?

Did your car have 2 or 4 Oxygen sensors (Lambda sensors on the other side of the pond)? Where was your car originally sold? What did you do with the sensors? Show pictures of where installed.

Classic outcome of messing with the emissions/exhaust.

Johnny Danger · 04-08-2013, 10:19 AM

I'm guessing that it's an RoW model that has no pre-cats, and after removing the secondaries the vehicle was rendered catless. Thus, the CEL.

shadrach74 · 04-08-2013, 03:50 PM

Quote:

Originally Posted by Johnny Danger

I'm guessing that it's an RoW model that has no pre-cats, and after removing the secondaries the vehicle was rendered catless. Thus, the CEL.

I don't believe the ROW cars have a post CAT O2 sensor, so the ECU has no idea if a ROW car is running with or without CATs. I've no idea how cars are delivered in Sweden, which is why speculation without the codes is just that...

mikefocke · 04-08-2013, 05:38 PM

Just because he lives in Sweden doesn't mean the car was delivered there originally. Which is why the questions about what he had on the car before his mods and what he did with the sensors afterwards.

shadrach74 · 04-08-2013, 07:36 PM

Quote:

Originally Posted by mikefocke

Just because he lives in Sweden doesn't mean the car was delivered there originally. Which is why the questions about what he had on the car before his mods and what he did with the sensors afterwards.

A flashing CEL accompanied by an engine miss is classic with the emission/exhaust? I redily acknowledge that you know way more about Boxes than I ever will. However, I can't tell you how many times that coincidence has caused me and others I know to go down a rat hole because "it must have been the .... that was installed last week!" For sure I've seen a lot of mod/maintenance induced failures as well, but a flashing CEL and a miss are not symptoms of any O2 sensor/high flow exhaust issue that I've ever encountered.

What is "classic" about it? I have to assume you've encountered something similar before...

x-itingcars · 04-08-2013, 09:45 PM

Hi Again!
My car was sold i new in Italy and exported to Sweden e few years ago. The car had two original cats. The oxygene sensors is now sitting in the end of the headers. As Shadrach74 wroute. I have to check the diagnostic codes to make sure. If somone is interesting of more pictures of my "Boxster projekt" you can check it out on facebook at x-iting cars Uddevalla jocke"
Now i have to go to work! Best regards Jocke x-iting cars Uddevalla/Sweden

mikefocke · 04-09-2013, 05:54 AM

Last touched, first suspected. Plus while working, he may well have disturbed something. Which is why first thing is get a look at the codes.

As I read the forums, I see people all the time struggling with getting their emissions related warnings under control after changing the cats. Be the first to admit I don't know much about ROW cars but if we can get some facts out maybe others can help. It's the specifics we lack.

x-itingcars · 04-09-2013, 09:32 PM

HI!
I have left the car at a garage to read the codes. Now i can just wait. Get bak when i know moore. Best regards Jocke Sweden

Homeboy981 · 04-10-2013, 03:24 AM

Yes but how was it driving up to the point of the CEL? You should be smitten with the performance of the new exhaust system. Did you add an intake too?

What is puzzling me is that the "known" solution for US cars (with 4 cats) using headers and a full exhaust is to go with a RoW Flash. Haven't you been flashed? If so, that would render the catless issue to be a non-event.

Which is why a smart person once said. "Last touched, first suspected. Plus while working, he may well have disturbed something."