a few days ago i noticed a "ticking" noise starting to form on the drivers side coming through the firewall.. it has gradually gotten worse and then check engine light came on. took it to autozone got the codes run. something about reverse airflow need to replace DPFE sensor.
is the ticking noise possibly associated with this?
i am pretty sure the DPFE is not your cause of the tick! I had to replace my DPFE in my 96, there was no tick before or after replacing it. It sounds like you may have a small exhaust leak if you can hear it through the firewall.