My sisters Taurus has been throwing fits lately.
Some days it surges while driving. This morning it just refused to
restart without some help from the pedal.
I recently pulled off a P0430, Catalyst efficiency below threshhold,
This sounds like either a cat or an 02 sensor. What I've read up on
so far, it sounds like the cat.
I've heard in the past, that "cat's don't just die. They're killed."
If I swap out the cat, would it also be wise to go for the 02 sensors?
I'm worried the one(s) on the manifolds are telling lies, causing the
So... If so - All of them? How much do they run?
============================All that code means is the CAT isnt cleaning the exaust. It has nothing to
do with your running problem. Sounds like the car needs a tune up or some
other problem not related to that code. I would start with plugs and a fuel
If you do wind up getting a CAT for it, go to a muffler shop and have them
put one on for about $100.
What are the parameters for 'cold startup'?
Yesterday it refused to start back up after it was already
sitting in the driveway for 20 minutes, warming up. It was
about 45*F outside.
What I'm worried about, is that the manifold 02 sensors are
not accurate... sending wrong info to the computer... which
is putting a wrong A:F ratio into the engine. An overly
rich mixture will kill a cat, correct?
I'm worried that if I don't look into what caused the cat do
crap out, it'll happen again with the new one.
The engine has been gone through as far as tune-up stuff goes.
Wires, plugs, fuel filter, air filter, all that fun stuff.
There are no codes on the computer anymore...
The car has 140K miles on it. The only thing new to the car
is a valvetrain, a battery, and the above mentioned parts.
Do these engines have distributor caps? I didn't get a chance
to really look at the square thing.
I believe it is more likely there is a problem in the closed loop
system, forcing the F/A ratio controller to operate outside of
its design parameter thus contaminating the 02 sensor. Have it
diagnosed by a system analyzed and correct the fault, WBMA.
Something as simple as a bad plug wire can eventually contaminate
the cat and the sensor
Marc Westerlind wrote:
============================Ok, lets start over. The O2 sensors will have NOTHING to do with a hard to
start condition, cold or hot or anything in between. There is no dist cap.
Besides the check engine light and code for ineffecent cat, the only problem
is it seems hard to start? Please explain exactly what you mean....You said
you have to give it a little pedal and it will fire right up? Earlier you
said it surges a little? please explain exactly. With that many miles on the
car it wouldnt hurt to change the front O2 sesors, but it wont fix your
starting problem. Also with that many miles on the car the CAT is probably
bad, even if nothing else is wrong. Yes a rich running condition or a miss
will kill the CAT prematurely. If it is hard to start but a little pedal
will get it going nicely, start by cleaning the throttle bore if it is dirty
and clean the IAC too.
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
Distributorless... easy enough. I didn't recognise it.
Both of these problems both popped up in the last week. The code was
about a week and a half or two weeks ago.
While driving, fully warmed up, at random times, the engine will surge
or stumble a bit. I couldn't get a more detailed explanation, or take
the car out myself.
The other morning, the car was idling in the driveay warming up, for
about 20 minutes. My sister shut the car off, and went to restart it a
few minutes later. It did not want to start like a normal fuel injected
car should, with a simple turn of the key.
She gets on the phone and calls me. She tried a number of times to start
it with just the key. I'm lost as to what to tell her. I fall back on
the method on starting an old carbed engine, and tell her to tap or
modulate the throttle a bit while turning the key. If that don't work,
put the pedal to the floor and try it.
She came back saying that it started with a little throttle.
I haven't been able to catch up with her for the last few days to check
out the car any further.
That sounds good... thanks.
Just wanted to make sure the running/starting problems weren't tied in
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.