Formulals187

iTrader: (3)

My car sounds like it has been misfiring and has a distinct ticking sound, but there has not been a code thrown yet. I have checked that all the wires aren't touching the headers and that they are all seated properly. Whenever I am cruising at low rpms it misses pretty noticeably and idles really roughly. Last time I filled up the car I dumped in fuel injector cleaner, the car ran great with no ticking ran great and idled fine, now half a tank is gone and the problem persists. I replaced 2 coil packs on the driver bank, because thats where the sound seems like it is coming from. The sound is most noticeable underneath the car and not around the engine bay. What should I do, change plugs, something with the injectors?

LS6427

iTrader: (2)

Could have a leaky injector.
Check your fuel pressure at the rail.
Maybe a failing 02 sensor, have to get a scan with a real OBDII scanner to see how they are working while the engine is running. ((no, you won't get a light till it fails in most cases))


.

Formulals187

iTrader: (3)

Checked for leaky injectors and none appeared to be leacking.
How would I check the fuel pressure at the rail?
What code would be thrown if an O2 sensor is going out/failing?

1987firechicken

You need to get a scanner on it and pull the codes, all the codes it can throw are on a sticky. you check for leaking injectors by measuring the fuel pressure at the rail. There is a schrader valve on the driver side end to the front of the car. Put a fuel pressure reader on it and turn the key to let the pump put pressure to the injectors. Then key completely off and see if your constantly loosing pressure. You should be at 60 psi at key on and stay relatively close when you key it off.

If you pull the codes it will tell you which cylinder is missing so you can isolate your search. I'd pull the plugs and look for cracks in the porcelain. I had a misfire caused by a crack that would happen only under load. I'd look into these before moving to O2's since plugs and a fuel pressure check is WAY cheaper.

Formulals187

iTrader: (3)

Would it throw a failing O2 code since I had the code removed when I gutted my cats?

1987firechicken

On the rear O2 sensors....Yes but those don't matter. Only care about your front set before the CAT's they control your fueling.

Formulals187

iTrader: (3)

Whats interesting is that the ticking sound is only noticable from underneath the car and not in the engine bay

Formulals187

iTrader: (3)

I switched the driver side plugs today with plugs gapped at .050 instead of the .035 that the others were at and the car seemed to run pretty good.

Formulals187

iTrader: (3)

Stupid plugs appear to have been the issue

THE SHOP

I was about to add FIRST check basic tune up parts then mechanical failures like injectors, fuel pressure etc, sounded like you had a simple misfire.