Thanks, XXXXX XXXXX I need to clarify, originally they tried to cut and replace a piece of the exhaust, however a very poor weld job was done, they had trouble getting a proper closed weld so replaced the entire exhaust pipe.
After this while driving my check engine light came on, this is when they replaced some filters they said where clogged and I had a tune up done while it was in and all the trouble began.
The pulsation is periodic, comes and goes, no issue when driving as I said everything seems fine. Will try what you suggest. Thanks Stuart