Post turbo & front converter replacement project issues - P0234 & P0430 code

[josh_ruppert]

Hello everyone,

It has been a pretty busy few weeks but I have the Explorer Sport back together and driving. The vehicle runs decent but appear to be experiencing some issues.

I do feel a surge when accelerating. Sometimes is worse than others. At WOT, it will surge, as if power is being cut in and out. Once I get to around 65, it wants to hang there for a few seconds before shifting and struggles beyond.

I pulled codes and I get a P0234. On a long drive, I will also get a P0430.

For the P0234, I have inspected the vacuum lines. They are all connected. I have also swapped out the boost solenoid. This has not corrected the problem. I need to pick up a vacuum gauge to check to see if the wastegates are moving properly.

I have attached one freeze frame that my Forscan produced from the P0430 code. One thing I am noticing are high (positive) long term fuel trim's around the 14's. I have inspected for vacuum leaks so this leads me to believe it is a fuel related issue. I am aware that a bad or dirty MAF can cause numbers to be off, which is why I ordered the inexpensive MAP just to rule out.

For the P0430, I am not sure what to make of this. It is a new C.A.R.B certified converter. I am kicking myself in the butt because I did not replace the o2's during this project. The front downstream was replaced due to a bad connection. I may purchase new Motorcraft's and install. Just not liking the idea of throwing parts around.

Any thoughts?

 

[peterk9]

I found several threads on the P0430 code using the search feature. Here is one that is interesting. Fix P0420 P0430 for only 10$

Peter

 

[josh_ruppert]

I have seen threads with people trying the cat cleaner. But this cat is brand new. I have also seen where people put in the o2 extender. Just seems to me that it ought not to need any modifications.

 

[mguy13sport]

Replace the 02 sensors. Its going into limp mode I assume when the power cuts out. You could move the 02 sensors around and see if the problem follows if you wanted to be absolutely sure.

 

[josh_ruppert]

I found out what was causing my P0234. I took a vacuum pump and put it on the main lines going to the turbos. I pumped up some vacuum and noticed the vacuum drop. Upon further inspection, I found the rear hose to be damaged. I replaced the rear vacuum line and the car runs night and day difference.

Now for the cat code, I was getting just a P0430. After fixing the vacuum line to the turbo's, I am receiving a P0420 as well. So both P0420 & P0430. ugh..

The front converter is a new aftermarket (CARB) certified. The rear cat was not touched. I replaced the front downstream o2 during my project but did not touch the others.

Something else I noticed yesterday before finding the damaged vacuum line.. I used forscan and was datalogging injector. Not sure if anyone is familiar with Forscan, I am new to this and just scratching the surface. On one of the graphs, the injectos were switching from 0 to 4. Some were quicker switching than others. 5 and 6 were very slow to switch. I looked at the graph that shows the line and found 5 and 6 to having very weak and sporadic movements while all the others had clean up and down movements that were tight.