SL500 Check Engine Light On. Need Help!
 

Hi to All,

I have the check engine light coming on and off on my SL500 recently.
I had the fuel filter, air filters and spark plags replaced last month.
It has 91K miles on it.
I had the car scanned today, and had the following codes stored:
PO305, PO306, PO307, PO308 (cylinder 5,6,7,8 misfired)

Also PO150 which is a front oxigen sensor in bank 2. I like to know if that is the driver side as I was told or not.

Also PO300 which is a random misfire and PO410 which is a malfunction in the secondary air injection system.

I was thinking about to have the driver side oxygen sensor replaced first.
Can that cause the misfire? What else should I have checked?
One more thing I should mention. If I floor the gas padal, it looks like half the engine shuts off and loose the power. If shut off the engine and restart, all cylinders are working.

Any help would be highly appreciated.

Thanks!

Sorry I forgot.
 

I forgot to mention that it is a 1999 model.

Thanks,

Brian

There's a very good chance that the mis-fire codes are being caused by the faulty O2 sensor. Since the entire left cylinder bank is throwing mis-fire codes, replacing the left O2 sensor is the logical place to start (especially since there's a fault code for it). I've seen clogged catalysts' cause similar problems, but the O2 sensor is the most likely problem.

There's also a chance that the P0410 code is being caused by the O2 sensor as well, since Air Injection function is checked by monitoring the O2 sensor voltage during air pump operation.

I'd start by replacing the drivers' side O2 sensor and clearing all the codes.

Thank you very much!
 

Hi ILUVMILS,

Thank you very much for your advice! I will replace the O2 sensor, and see what will happen.
I do really appreciate your reply!

Brian