If I filed chapter 13 4 years ago and I kept up mortgage payments, if I let it foreclose now will it affect me?

Probably not. But if you want a definitive answer, pay an experience BK lawyer for one hour of their time to review the file with you.

The answer depends upon how the mortgage loan was treated in your chapter 13 plan. If you cured an arrearage then the debt was not discharged. You may want to contact your chapter 13 lawyer to try to determine whether the mortgage loan was discharged or not.

I have only seen a few situations in which a first mortgage lender pursued a debtor for a deficiency on a real estate loan, and in the few instances I have seen, not one had filed a Chapter 13. However, a short sale may be a far better alternative to you than foreclosure and can put some cash into your pocket.

Your question is a mite unclear: Do you mean that if you stopped making payments and the creditor filed a foreclosure action against the real estate, will it affect your credit score? That's a very interesting question. If you did not sign and file a formal reaffirmation, then the mortgage note, the promise to pay, was discharged at the end of the Ch. 13, but the mortgage-holder can proceed against the real-estate. My guess and this answer is no more than a partly-educated guess, is that such a foreclosure would likely have an adverse effect on your credit score. Even though the foreclosure is against the real property and not against you personally, the practice everywhere I know is to name you as the defendant in the foreclosure. It doesn't have to be this way: the legal action could be titled LENDER vs. 284 Pine St., Plainsville Iowa, but that is not the way I've seen it done. Good Luck.

In a Chapter 13, you remain liable for your secured debts (unless you surrender the property). So if you let it foreclose, you'll be liable for any deficiency (the house doesn't sell for the loan amount - and it never does because the costs of a foreclosure are extremely high), and you'll have a foreclosure on your credit report.

If your plan treated the debt as a continuing debt pursuant to section 1322(b)(5) it was not discharged in your chapter 13 bankruptcy and would be owed today. If the home is foreclosed resulting in a deficiency you would still owe the money.

Yes, it will.