After taking my 99 caravan 3.0l V6 to the dealership for diagnostic because of service engine light and poor idle I was told to replace downstream o2 sensor as well as plug wires. After replacing I disconected battery to clear codes, started it up and now has a bad miss and it back fires through intake. Triple checked all plug wires and o2 sensor. What the heck??????
Anyone have any thoughts or know whats the problem with this thing? Also this is my first time using the forum so please help.
paul8502
10-06-2005, 11:15 AM
Come on guys anybody out there able to help me out just a little bit. I just cant seem to figure out the problem with this thing.
gas28man
10-06-2005, 12:54 PM
You had a problem before, and there are only three possibilities: the things you changed either made it worse or introduced a new problem, or the new problem is just a coincidence. I wouldn't suspect the O2 sensor. Good or bad, it's just not capable of producing the symptoms you have.
First thing I would do is check the codes again.
The second thing I would do is to not assume that new plug wires are necessarily good plug wires. Find a way to do some "known good" swapping of these.
Then I would look at the primary ignition circuit. Does the 3.0 have a coil pack or a distributor? I'd look at either of those two first. Another possibility is that your timing belt has slipped. You might also have a faulty crank and/or cam sensor (I can't remember which the 3.0 has). These, by the way, may or may not show up in trouble codes.
Good luck, and let us know what you find.
Rick
paul8502
10-06-2005, 04:58 PM
Anybody else have any ideas before I jump in again?
96Grand
10-09-2005, 10:43 PM
I would suggest that you get the trouble codes from the dash if there are any... & then post them here & we can tell you what they mean.
• Start with the ignition off. Within five seconds, switch the key on, off, on, off, on. (On is *not* start!)
• The "check engine" light will flash. Count the flashes Each code is a two digit code, so a (for example) 23 would be FLASH FLASH (pause) FLASH FLASH FLASH (long pause)
• It will never flash more than 9 times, watch for pauses!
• 55 is end of codes - it's normal. Before you call your dealer or mechanic, consider that the blink-spacing is not always perfectly uniform, so if you see 23 23, it's probably just a single 55. (Codes are not repeated.)
paul8502
10-10-2005, 02:16 PM
Took van to dealership, did scan and cylinder efficiency test and it turned out perfect with no codes however Ive got a new problem. That coincidently happened the same time the old problem was fixed. Checked timing belt and EGR. I think the problem is vacuum related cause I can here a whistle.
Thanks Rick and 96Grand everything is very helpful.
