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CEL On SL55 (R230) highy modded car O2 sensor issue

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Old Jan 3, 2016 | 08:38 PM
  #1  
Planb51's Avatar
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From: OC-CA
2003 SL55
CEL On SL55 (R230) highy modded car O2 sensor issue

Please help!
Looking to fix my Check engine light issue. Just got a sl55 and the CEL light is on.

Looking for ideas on how to California pass smog in the future and correct the CEL light issue.
The car is highly modded and it would seem this is a factor since the after cat O2 sensors were just replaced.
Not sure if the new senors are universal or factory.

The car was tuned by OE tuning but I don’t know when.

Cleared the CEL codes and it came back on the very next day

Also with the codes, does this mean the car is running in limp mode?

Codes pulled are
P2098 - Post Catalyst Fuel Trim System Too Lean Bank 2
P0141 - O2 Sensor Heater Circuit Malfunction Bank 1 Sensor 2



Known upgrades this car has:
OE tuned
Floored fab Long tube headers
Floored fab mid section x-pipe
200 Cel Cats (No 2nd cats)
Stock mufflers
Floored fab Custom intake
Custom 82mm Throttle body with CNC machined bored S/C sleeve
ASP custom 185mm Pulley
Dual I/C pumps

Front mount Heat exchanger
Trunk mounted Remote Reservoir separated cooling circuit

Thanks a ton guys, Any ideas on what direction to go would be great. Maybe have it tuned again? Take it to my local shop? Just nervous to take it in to shop that doesn’t know how to factor in the issue with all the mods this car has.


I have heard of O2 sensor issues with the Floored fab headers and Cats. Maybe this is the issue?
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Old Jan 4, 2016 | 12:46 AM
  #2  
knowbenz's Avatar
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Im pretty sure there are capable shops in OC. 200 cel cats are fairly small maybe they arent cleaning up the exhaust enough? Just spit balling. Also universal o2 sensors suck so i would try and find out which ones were installed
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Old Jan 4, 2016 | 12:55 AM
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Stephen Garcia's Avatar
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'04 C230K Sedan
Wow you're trying to pass smog and have a custom exhaust... Let me rephrase: you're trying to sneak the smog test in cali.... Waste of time. They'll get you every time. Cali is like the ***** of the U.S with emissions.
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Old Jan 4, 2016 | 12:59 AM
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'04 C230K Sedan
My guess would be that your o2s aren't sniffing that exhaust well, post cats.

If you have cats (don't want to hit the back button to recheck)

You might have to get some dams to direct the fumes to the o2s.

Many different ways to do so if you go to the person who knows what your problem is
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Old Jan 20, 2016 | 12:44 PM
  #5  
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16 GLC 19 Volvo XC40 06Corvette Z06
Whatever you do don't take the car to the dealer. When they become aware of the modifications they may take action to void the vehicle warranty (assuming warranty still in force).

In most cases when you do upload a revision to the ECU the tuner turns the rear O2 sensors off (assuming you still have the aft sensors).

Ideally, if possible, would return the car to the shop that originally did the modification/tune.
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