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Code P0430. Hesitation Below 3500 RPM.

8

816SVT

New CEG'er
Joined
Jan 24, 2010
Messages
22
Location
Excelsior Springs, MO
I have a code P0430 (catalyst efficency below threshhold) (bank 2). I also have a light miss/sputter/hesitation below 3500, could this be due to a bad O2 sensor? If so, which one do i change? Which side of the engine is bank 2? Which o2 sensor tells the computer how to mix air/fuel? Is this an o2 sensor problem at all? I have had the code cleared several times, but i rev the engine and it comes back. My car runs great above 3500 RPM's, but me living in the city (with stop and go traffic), it tends to get on my nerves a little. Please help, I am new to this.
 
You should have just stuck with your other thread- no need to repeat (even though I may be guilty of this..)

Bank 2 is the radiator side (I think, but i have a 50% chance I'm right.. :laugh:)

Upstream O2 changes fuel/air mixture
Downstrem O2 measures cat efficiency

yes this could be an o2 sensor issue.. but so many things can cause this. Vacuum leak, bad O2, leaky injector etc. If there is no lean/rich codes, I would assume the upstream sensors are OK. I have read in the past that the coolant temperature sensor can even affect the cat efficiency readings; after all, a cold/cool engine is fed more fuel.

There was also a Technical Service Bulletin on this issue requiring the computer to be relflashed by the dealership.

Hope this helps.
 
read your other thread for the hesitation problem and DO NOT make new threads about the same thing. As far as the P0430 goes, use the search feature, it's there for that reason.
 
greasemonkey1489 said:
He's just wants answers..
Click to expand...

i know, but then when a new batch of noobs come here with the same problem, if they search for hesitation under 3500, theyll get both threads, and only 1 will have an answer. I just wish this forum had a feature like some sites like dell do, where if you have a computer problem, and go to ask a question, you type "my computer will not turn on" and when you go to ask it, it comes up saying "we've found these topics with similar titles. Do these solve your problem?" and you click yes, or no. Someday maybe forums will be like that. :shrug:
 
816SVT said:
I have a code P0430 (catalyst efficency below threshhold) (bank 2). I also have a light miss/sputter/hesitation below 3500, could this be due to a bad O2 sensor? If so, which one do i change? Which side of the engine is bank 2? Which o2 sensor tells the computer how to mix air/fuel? Is this an o2 sensor problem at all? I have had the code cleared several times, but i rev the engine and it comes back. My car runs great above 3500 RPM's, but me living in the city (with stop and go traffic), it tends to get on my nerves a little. Please help, I am new to this.
Click to expand...
For the P0430, get mileliminators installed for the lower bank 2 sensor. This is the sensor below the Bank 2 catalytic convertor (radiator side).

For the <3500 RPM sputter, check that spark plug wires are not loose. In addition, when was the last time the spark plugs were changed? Another thing which could cause the sputter is a bad IMRC Intake Manifold Runner Control.
 
I checked the spark plugs (all of them), they all look good. Spark plug wires look fine as well. Runs hard after the secondaries open up (3500 or so RPM). Dont know anything about the IRMC.
 
That's what he means by IMRC. Intake Manifold Runner Control- It's a servo that actuates your secondaries. However, the engine computer is tuned to change fuel mapping etc after they open up. If they are stuck open, there will be a hesitation below 3500. To check this, open your hood and find the throttle linkage on the throttle body. Raise the RPM's (maybe have a friend watch the tachometer) until 3500-4000. Watch carefully for movement of any linkages directly below your throttle body. If nothing happens, your IMRC box or cable is more than likely shot.
 
p0430

p0430

Possible causes
CATALYST EFFICIENCY MONITOR
Diagnostic Trouble Code Description Possible Causes
P0420 - Catalyst System Efficiency Below Threshold (Bank 1) Indicates Bank 1 catalyst system efficiency is below the acceptable threshold.
· Malfunctioning ECT/CHT
· High fuel pressure
· Damaged exhaust manifold
· Cylinder misfiring
· HO2S wiring concerns (shorted or chafed, bent pins, etc.)
· Damaged exhaust system pipe
· Damaged muffler/tailpipe assembly
· Retarded spark timing
Damaged Catalytic Converter:
· Use of leaded fuel
· Oil contamination/consumption
· Silicone contamination (sealants/cleaners)

P0430 - Catalyst System Efficiency Below Threshold (Bank 2) Same as DTC P0420, but opposite bank. See Possible Causes for DTC P0420
Please note that the O2 sensor is number 4 on the list from ford trouble shooting guide. Take a good look at the number 1 item. Engine coolant temp sensor. If this is not reading correctly your computer can and will not deliver the correct amount of fuel. Easy and cheap to change. The entire service bulletin can be found at the following link
http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm
 
Cleared the code and it has not came back, but it still seems to have major hesitation (under full throttle) below 4000 RPMs. After 4000 its like magic, all the hesitation disappears. :shrug:. The vehicle seems to have a miss, but no misfire code is present. Sometimes I even have to crank it a few times to get it to start. I only use PREMIUM unleaded fuel and have even added that Berrymans B12 fuel treatment.
 
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