Before I replace the EBP sensor....

[ttyR2]

I have a "service engine soon" light on. An ODBII scanner turns up the error code related to "exhaust back pressure too high". I cleaned out the EBP sensor (it was packed full of carbon), and rotor-rooted the carbon out of the EBP tube and fitting, but still get the same error. Is there anything else to check before replacing the EBP sensor? Best price I've seen is $72 for new OEM.