Hi all

I recently bought a 1999 CLK320 with 160 000km on it, but it is pulling a P0410 Secondary Air System code.

My mechanic said it is mostly likely the airpump, but i've been doing some reading and I figure i should try and replace the relay first before buying an airpump.

In regards to that, would a faulty air pump cause a rough idle while cold? My car will idle very rough and rpms drop slightly when stopped at a light for example.

I know there are alot of threads covering this, but i couldn't find if the rough idle is caused by the airpump as well.

I appreciate any help you guys can provide.

Thanks
Varun.

 

What air pump are you referring to? I wasn't aware the 320(I have one too)had an air pump. Perhaps there is another term for what you are describing?

 

It's also known as a Smog Pump I believe... It's located front and center right under the engine cover.

 

could causr rough idle at cold start up but not when warmed up unless theres a leak in a hose

 

Great.. thank you.. I will try to change the relay if that doesn't work I can change the pump completely..