My car started hard starting last night. Check engine light came on and got codes around the O2 sensor. It previously had a code on a misfire cylinder, so I bought new plugs and coils and installed them today. Check engine light went away but the hard start is still happening. Turn the key, it cranks and stalks out. Turn the key again and it fires up. It smells like it’s running rich as well because I’m detecting an exhaust smell.

could this be an issue with the fuel pump or filter? It’s not pulling any codes for fuel pressure. Any help in the matter is appreciated.

 

Welcome to the site, please post the actual codes .
Engine , year, mileage transmission

 

ie: what was the code for the O2 sensor, as well as the one regarding the misfire.

Swapping plugs and coils between the cylinders might have been a much better (and cheaper) diagnostic technique

 

Always do this when asking a problem.

 

code P1811 and code p1133. 07 hhr, 258000 miles. 2.2 engine. The plugs and coils had never been changed which is why I invested in parts to do that. It cleared the check engine light, but still hard starting and smells like it’s running very rich on the fuel because I’m smelling exhaust in the cabin. I’m going to take it to have codes checked again later today to see if anything else is there.

 

https://www.transmissionrepaircostguide.com/p1811/

check the MAF sensor, and clean it.

https://ericthecarguy.com/kunena/8-S...ine-code-p1133

O2 sensor


check the flex pipe for cracks also, that will cause fuel orders in the cabin, so will a corroded fuel vapour line

 

1st thing to check would be the flex joint on the exhaust. That's a known weak spot, prone to failure. It's located at the exhaust manifold and connects the manifold to the exhaust.
If it is cracked, then it's most likely the cause of the O2 sensor codes.