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Amedee, Former ASE Master Tech
Category: Car
Satisfied Customers: 24128
Experience:  ASE certified tech advanced level specialist. Wisconsin certified emissions state inspector
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2004 Suzuki Verona: p0301, p0302..Oxygen sensor..runs warms

Resolved Question:

Our Shop has a 2004 Suzuki Verona with p0300, p0301, p0302, p0303 and Oxygen sensor code. It runs fine cold and when it warms up it does not want to go
Submitted: 4 years ago.
Category: Car
Expert:  Amedee replied 4 years ago.
Hello and Welcome to Just Answer. My name is AMEDEE and I will try my best to assist you and your 100% satisfaction is my goal. I have been working on these vehicles for over 10 years so I am very familiar with this system and how they work. However, keep in mind, that I need some solid concrete facts/evidence/clues from you in order to give you a good answer about your vehicle. Please realize that all my answers are based solely on the info that you provide me with.

Are you saying that the engine bogs down or hesitates when trying to accelerate when the engine is warm?

Does it idle ok? Have you checked fuel pressure or engine vacuum?
Customer: replied 4 years ago.
I would have to check with the Tech at the shop in the morning but everything appeared to run fine. The customer suspected catalytic converter but this is not a symptom of a converter.
Expert:  Amedee replied 4 years ago.
I agree. A converter will be plugged cold or hot. Usually it does not affect the engine just when it is warm.

Have you checked fuel pressure? I take it a tune up was done correct?

How does the engine idle?
Customer: replied 4 years ago.
idles good and only has 84k miles. The customer states that they bought the car and it ran perfect for a week than all of a sudden it did this. I have seen repair problems with PCM also as well a MAF Sensor and the codes is only affecting one bank. We will have to check fuel pressure.
Expert:  Amedee replied 4 years ago.
I was just going to mention the MAF sensor too..

Let me do some research for you and post back in a few minutes. Would that be ok?
Customer: replied 4 years ago.
yes. We cannot find much info to guide us on this make and our scan tool has Suzuki but getting live data is impossible.
Expert:  Amedee replied 4 years ago.
This engine should be a straight 6. This means that one camshaft could not be off affecting one bank. This would cause both banks to be off. You do however, have two converters on this engine. I suppose it is possible that one is partially plugged and the brick inside the one of them heats up and expands restricting air flow when warm/hot.

Another thing could be a bad camshaft position sensor. but this should affect all of the cylinders. Same goes with fuel pressure. It should affect all cylinders but it may not be flagging a code for the other cylinders. Or course, it is possible for one of the o2 sensors ot be bad.. but this should not prevent the engine from accelerating.
Customer: replied 4 years ago.
We did some inspection underside and cannot find a place to check fuel pressure. The other way is at the fuel filter. When we got the vehicle up wwe founf that someone has replaced/Rigged the fuel filter and the line has a kink to it so today we are going to try and fix that first. On the computer one bank is running lean while the other is running rich, but yes since this is a straight 6 it is a little different.
Expert:  Amedee replied 4 years ago.

Based on my experience, I would go after the bank that is running rich. Sometimes the bank that is running lean is compensating for a rich condition causing it to run leaner than it should. However, this does work both ways and it could be the other way around. Just some ideas.

Let me know what you find!
Amedee and other Car Specialists are ready to help you
Customer: replied 4 years ago.
We checked fuel pressure and its in specs. We swapped coils from Cylinder 1,2, 3 to Cylinder 4, 5, 6. Drove it a few 100 yards and skip came back to original cylinders. It did not move with the coils. We might be sending it down to a shop that has the Factory scan tool. He will hopefully help us since he can look at more data.
Expert:  Amedee replied 4 years ago.
Sounds good!

Thanks for the update!

Keep me posted!