My 99 CV keeps throwing a PO 302 code.
I'm baffled by this one.
I was coming home from a 1000 mile trip. I bought gas at a station I have bought from before in AZ. After gassing there we headed back & I got real bad mileage like 15.6 mpg. First thought bad gas. Fueled up about 160 miles up the road & filled with Union 76 gas. threw in a can of Seafoam. The second tank gas mileage improved but below normal. (I run this trip every month) Just before the third tank 100 miles from home the CEL comes on. I carry a reader & a PO302 code shows. I fill up Union 76 again. clear the code throw in a little Lucas injector cleaner. Get home drive a day in town another PO302. Fill up again Union 76 gas. Drive in town 3 days another PO302. This CV had new plugs AP104 Autolite plugs, new boots & springs, about 10,000 miles ago. So I put in a new fuel filter, PCV valve, changed out the #2 plug & swapped the coil with #3. checked all connections put Di-electric grease on connections. I still have a PO302 code showing up.
Any ideas or help PLEASE. Thanks in advance.

 

try wiggling the injector electrical connector and see if the miss goes away.
on my crown vic, all 8 injector connectors deteriorated and started loosing connections causing random misses all over the place.
since i replaced all the connectors not one miss. .

 

Thanks for your response.
I noticed the injector connector clip is broken. I did Di-electric the connection but maybe I need to replace it. The funny thing is I never feel the miss but my reader keeps picking it up even at an Idle. I can clear it & it will run for awhile just fine then pop the PO302 code again. The big thing I notice is the gas mileage.

 

the interior red separator moves when the clip is broken and the connections make and brake. the connectors are only $10.36 each from rock auto.

BUT... there are 4 or 5 different connectors, you need to know exactly which one you need .they have pictures for each one so it is not that hard to match them to the one you have.
this is the one my 99 uses: STANDARD MOTOR PRODUCTS HP3945

here is the link with a picture so you can see what it looks like: http://www.rockauto.com/catalog/moreinfo.php?pk=4673319&cc=1354407&jnid=608&jpid=4

 

I took a plastic tie & ran it through where the lock clip is broken from around the injector & the connector is tight to the injector now. It might of been the issue. I'm not showing a code in my reader anymore. After a short drive it seems to be OK. So I will drive it & see if the CEL stays off. Thanks to everyone for your help & responses. I'll update in a few days. I'm always amazed at how real little things trigger the codes on this Crown Vic. A slightly loose exhaust manifold to pipe bolt set off the CEL with a lean bank code. Heck I only was able to tighten the bolt a turn or so. That happened twice.
PS: I ordered a new connector. I'm in a very small town 100 miles from much. But we do have a NAPA store.

 

that bad connector drove me nuttier than squirrel turds for 3 weeks trying to find it. i change coil, plug another coil, and finally went to pull the injector and the miss went away as i touched the wire. then it came back the next day, and i pulled the connector off and saw the center piece was jacked up.

 

The funny thing with this is I never really felt a miss. The clue to me was the poor gas mileage. As a rule I feel misses. Thanks for your help.

 

The fix is working, so far. I think I will zip tie all of them. That way they can't come loose. Guys over at the Crown Vic forum are suggesting that.