Sorry, just a little frustrated trying to track down a component I am not familiar with. I suck at the electronics and while looking at the schematics found the temp sensor and that it was only $30, I guess that after sleeping on it you are right, I should check it before if I replace it. But I cannot locate and air injection system. Is it possible that was a California only emmission device?

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1981 300TD
2005 C55
2004 E500
1999 ML430
1992 400E
1998 C43
2001 SL500
1988 300SEL
1986 190E 16V
1991 190E 2.6